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Originally, life evolved from non-living matter. Why is life only generated from other life nowadays, and why doesn't it evolve from inanimate matter, like it did originally billions of years ago, when life evolved on Earth?
Maybe I should reword this further. Living organisms reproduce other living organisms but the first living organism came from non living material or chemicals. So could life be created in a laboratory as it originally was ? Originally the process leading to a life form took one billion years, so would this be the answer to my question that it takes too long and that is why it is not being repeated again ?
Abiogenesis, the development of living things from non living matter, is not something we know much about, since it happened about 4 billion of years before we were around and haven't reproduced it in the lab. My guess is that it's not easy. However, the Miller-Urey experiment and others have told us something about abiogenic production of organic compounds.
The first living organism on Earth ( Let's imaging some self-replicating RNA ) was probably very inefficient, copied itself slowly and made a lot of errors. At the time it could survive because there wasn't any competition. However, as time went on some of these copies were more efficient and copied themselves more quickly, outnumbering the original sequences and driving them into extinction. Wait another 3.5 - 4 billion years and you have modern life.
If abiogenesis were to occur on Earth today, the resulting organism would likely be inefficient like the first organism. However, now it would face immense competition from very efficient modern organisms and would probably be eaten.
This is speculation, but I assume that any new type of life on Earth would be carbon based, since organic carbon based building blocks are abundant. If anything, abiogenesis might be easier on modern earth than early earth because the starting materials (nucleotides, amino acids) are readily available, but competition from modern life and reactive oxygen in the atmosphere would hinder any new abiogenesis.
There are two questions here:
- Why does life only generate life?
- Why doesn't life continue to be generated on Earth?
The first one is easy. We don't only generate life. If that were true, it might be illegal to flush toilets. Life forms of some kind would occupy all the space in our atmosphere. Babies - or some living things - would rise up from our graves. Conceivably none of the millions/billions of people who have died from the beginning of history (and well before that) would be dead. Add to that animals, and everything in the other Kingdoms included in Life, and there would be nothing left perhaps except for life. To be honest, life generates heat, death and simple substances much more commonly than it generates life.
If you mean, why does like produce like (in your case, a life generates a similar life form*, that's because of genetic material. New life is based on the genetic material of the preceding life form. People don't give birth to zebras, zebras do. When the genetic material is damaged enough, we give birth to a non-viable or diseased child. If a mutation is favorable, it is (under the right circumstances) spread through an advantage. An example of this is the appearance of lactase, an enzyme which allows adults to derive continued nutrition from animal milk.
As to your second question: why doesn't life continue to be generated on Earth? Are you 100% sure that it isn't happening? How would you recognize a life form foreign to our own? How many different kinds of life can evolve under the same planetary conditions, the same planetary element ratios, etc.? If a very rudimentary silicon-based life form evolved in, say, the last 2,000,000 years, would you know how to look for it? In other words, are you defining life only as we now know it - a carbon based, DNA-propigated form?
Furthermore, if a non-carbon based life form could only evolve on this planet to a very basic, simple level, would you give credence to it as a newly evolved "life" form? Intelligent life is rare. I would guess that very simple life forms are far less rare in the Universe.
How would you classify (or explain) the chemosynthetic bacteria that oxidize sulfur instead of oxygen?
I realize that there are a lot of questions here and not many answers. But part of finding an answer is asking the right questions.
The Origins of Lactase Persistence in Europe
Abiogenisis, where imperfect micelles (spheres) of hydrophobic carbon chain formatiions leads to potentials for capturing and mixing elements and molecules forming peptides, polypeptides and protiens that can then catalyze enzymes to patterns to the micelle to a cell of sorts.
Was it inside a terrestrial micelle that life formed or Did amazing spiraling symetry of life get help or even need it from galactic wave patterns, crystal energy of minerals or was it just a mixing up microscopic pieces of Pythogerian parts and geometry.
Either and anyway, given low energy potentials needed for effeciency of a new life form, unless it was non carbon based, it would have practically zero chance of survival where energetic mass of life that already exists just chews it up and mutates spin offs. Only a dynamic shift in genetics as we know it would allow us to detect divergent life.
That said, got to love the ugly waterbear.
Origin of Life: Early Earth Environment
So if Pasteur is correct and life only comes from existing life, where and how did life begin? Many theories attempt to answer this question, including the popular creationist theory, which states that God created man in his own image, which may in fact be correct. However, this section illustrates the scientific evidence that leads to an evolutionary pathway. In the final analysis, both theories may turn out to be the same.
Based on many assumptions, the conditions on early Earth, some three to four billion years ago, are thought to be much different from what they are today. To begin with, the astronomical phenomenon called ?the big bang? is defined by a theory proposing that the earth was one of the larger particles that coalesced after the initial universe explosion, or big bang, that spewed all the particles in the universe away from a central point and destined them to slowly revolve around that point.
Iron-containing rocks reportedly recovered from period strata contain no rust, further indicating the absence of oxygen.
Consequently, the earth was very hot, evaporating the liquid water into the atmosphere. However, as the earth cooled, gravity-trapped water vapor condensed, fell as rain, and did not boil away but remained impounded in pools that became lakes and oceans. It was also believed that tectonic activity caused many volcanic eruptions at that time. From present-day volcanoes, we know that when they erupt, they release carbon dioxide, nitrogen, and a host of nonoxygen gases. In addition, with no protecting atmosphere, the earth was constantly bombarded with meteorites and other space debris still in circulation from the big bang. From current astronomical research, we know that meteorites can carry ice and other compounds, including carbon-based compounds. Researchers believe, therefore, that early Earth's atmosphere consisted of water vapor, carbon dioxide, carbon monoxide, hydrogen, nitrogen, ammonia, and methane. Note that no oxygen was present in early Earth's atmosphere!
Meteorologists suspect that lightning, torrential rains, and ultraviolet radiation combined with the intense volcanic activity and constant meteorite bombardment to make early Earth an interesting but inhospitable environment.
Two American scientists, Stanley Miller and Harold Urey, designed an experiment to simulate conditions on early Earth and observe for the formation of life. They combined methane, water, ammonia, and hydrogen into a container in the approximate concentrations theorized to have existed on early Earth. To simulate lightning, they added an electrical spark. Days later, they examined the ?soup? that formed and discovered the presence of several simple amino acids! Although this experimental design probably did not accurately represent early Earth's percent of gaseous combinations, further work by Dr. Miller and others, using different combinations, all produced organic compounds. As recently as 1995, Miller produced uracil and cytosine, two of the nitrogen bases found in both DNA and RNA. However, to this date, no living things have been made from nonliving things in the laboratory. Interestingly, continuing research on meteorites has identified, as recently as 1969, that they contain all five of the nitrogen bases. This presents the hypothesis that perhaps the ingredients necessary for life were brought from outer space!
Wegener: Plate Tectonics and Continental Drift
By looking at a modern-day map of the world, it is easy to see how the coastline of the west side of Africa appears to match the east coastline of South America. As cartographic skills and knowledge of the continent's boundaries increased by nautical exploration, in 1912, German meteorologist Alfred Wegener proposed an Earth-moving hypothesis. He hypothesized that the existing landmasses are actually moving and probably all began as one large landmass. His theory of continental drift made the landmasses of Earth appear like giant floating islands sometimes moving away, sometimes crashing into each other by forces he could not describe. Although the Africa-South America anomaly was noted, his theory did not gain much support in his lifetime.
Most of North America and about one-half of the adjacent Atlantic Ocean ride on the North American plate. The large Pacific plate rubs against the North American plate at the San Andreas fault in Southern California, creating frequent earthquakes.
With recent advances in geology, we now know that all the surface features?land and water?are actually floating on the viscous mantle of the earth, which supports the movable crust and outer layer of Earth. The solid crust, or plate, that we inhabit is one of many irregularly shaped pieces of varying size that move in specified directions. The idea that these large continental plates are in constant motion created by geothermal heating, convection, and movement is called plate tectonics.
Plate tectonics explains how large landmasses separate and also collide into each other. This constant Earth movement, often measured in centimeters per year, is responsible for earthquakes, volcanoes, sea-floor spreading, and continental drift.
Apparently, Wegener was correct the early isolated land forms probably joined together to create a single landmass, or supercontinent called Pangaea, approximately 250 millions years ago at the end of the Paleozoic era. Note in the illustration Pangaea the proposed shape of the supercontinent.
Life that had evolved on the separate landmasses now had to compete with other life-forms from the other isolated landmasses as these landmasses congealed into one. Competition for space, food, and shelter as well as increased predation created additional natural-selection pressures. Fossil records indicate mass extinctions and a major change in genetic diversity at this time.
A second cataclysmic event also affecting biological diversity occurred about 200 million years ago during the Mesozoic era. At that time, Pangaea began to separate, and the isolated land forms again became their own unique isolated evolutionary laboratory. The separating landmasses became reproductively isolated from one another.
Extinction and Genetic Diversity
Extinction appears to be a natural phenomenon and, like natural selection, favors the reproduction of certain species at the expense of less-fit species. Extinction is the loss of all members of a given species and their genetic complement, never to be recovered. Fossil evidence indicates that following a mass extinction such as the Permian extinction, when Pangaea was formed and again at the end of the Cretaceous period when dinosaurs ruled the world, a period of growth and genetic variation followed. Apparently, the extinctions opened the fringe territories for colonization by the remaining species. Mammals are the classic study on this point because they were known to exist 50 to 100 million years in territories inhabited by dinosaurs before the extinction of the dinosaurs. Following the demise of the dinosaurs, mammalian fossils indicate a considerable amount of speciation and growth in overall numbers, both probably associated with the acquisition of new territory and the loss of dinosaurs as competitors and predators.
Adaptive radiation is the process by which genetic diversity is increased in descendants of a common ancestor as they colonize and adapt to new territories.
The rapid genetic diversity following an extinction, landmass split, or other cataclysmic event may be due to adaptive radiation, also known as divergent evolution.
It is called radiation because the genetically divergent descendants appear to radiate from a central point, much like the solar rays from the sun. During div-ergent evolution, descendants adopt a variety of characteristics that allow them to occupy similarly diverse niches.
The classic example of adaptive radiation is the study completed by Darwin as he observed 13 different finch species during his famous voyage of discovery to the Galapagos Islands. The islands themselves are well suited for adaptive radiation because they consist of numerous small islands in close proximity in the Pacific Ocean approximately 125 miles (200 kilometers) west of Ecuador, South America.
Since Darwin's time, an analysis of the finch speciation revealed a founder population arrived from the mainland and occupied an island. Specific island pressures probably caused that species to evolve into a new species different from the mainland species. As the finches overtook the island, competition increased, and pioneer species may have migrated to a different island. This created a new founder species that adapted to the new island pressures and modified to become a new species. Likewise, the remaining islands were colonized in succession. Because each island is slightly different, the finch adaptations were often unique to a specific island. In addition, finches could return to an inhabited island and compete with the existing species, or return and divide territory, shelter, and resources and peacefully coexist. The return to an inhabited island also probably sparked additional natural-selection pressures.
We are still not sure how life originated on Earth. It could be a heavenly masterpiece, an astronomical anomaly, or a series of mutations and adaptations. There is evidence that favors each theory. Regardless, patterns in similarity appear to link some organisms more closely than others.
Earliest claimed life on Earth Edit
The earliest claimed lifeforms are fossilized microorganisms (or microfossils). They were found in iron and silica-rich rocks which were once hydrothermal vents in the Nuvvuagittuq greenstone belt of Quebec, Canada.
These rocks are as old as 4.28 billion years. The tubular forms they contain are shown in a report.  If this is the oldest record of life on Earth, it suggests "an almost instantaneous emergence of life" after oceans formed 4.4 billion years ago.    According to Stephen Blair Hedges, "If life arose relatively quickly on Earth… then it could be common in the universe". 
Previous earliest Edit
A scientific study from 2002 showed that geological formations of stromatolites 3.45 billion years old contain fossilized cyanobacteria.   At the time it was widely agreed that stromatolites were the oldest known lifeforms on Earth which had left a record of its existence. Therefore, if life originated on Earth, this happened sometime between 4.4 billion years ago, when water vapor first liquefied,  and 3.5 billion years ago. This is the background to the latest discovery discussed above.
The earliest evidence of life comes from the Isua supercrustal belt in Western Greenland, and from similar formations in the nearby Akilia Islands. This is because a high level of the lighter isotope of carbon is found there. Living things take up lighter isotopes because this takes less energy. Carbon entering into rock formations has a concentration of elemental δ 13 C of about −5.5. of 12 C, biomass has a δ 13 C of between −20 and −30. These isotopic fingerprints are preserved in the rocks. With this evidence, Mojzis suggested that life existed on the planet already by 3.85 billion years ago. 
A few scientists think life might have been carried from planet to planet by the transport of spores. This idea, now known as panspermia, was first put forward by Arrhenius. 
Spontaneous generation Edit
Until the early 19th century many people believed in the regular spontaneous generation of life from non-living matter. This was called spontaneous generation, and was disproved by Louis Pasteur. He showed that without spores no bacteria or viruses grew on sterile material.
In a letter to Joseph Dalton Hooker on 11 February 1871,  Charles Darwin proposed a natural process for the origin of life.
He suggested that the original spark of life may have begun in a "warm little pond, with all sorts of ammonia and phosphoric salts, lights, heat, electricity, etc. A protein compound was then chemically formed ready to undergo still more complex changes". He went on to explain that "at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed". 
Haldane and Oparin Edit
No real progress was made until 1924 when Alexander Oparin reasoned that atmospheric oxygen prevented the synthesis of the organic molecules. Organic molecules are the necessary building blocks for the evolution of life. In his The Origin of Life,   Oparin argued that a "primordial soup" of organic molecules could be created in an oxygen-less atmosphere through the action of sunlight. These would combine in ever-more complex fashions until they formed droplets. These droplets would "grow" by fusion with other droplets, and "reproduce" through fission into daughter droplets, and so have a primitive metabolism in which those factors which promote "cell integrity" survive, those that do not become extinct. Many modern theories of the origin of life still take Oparin's ideas as a starting point.
Around the same time J.B.S. Haldane also suggested that the Earth's pre-biotic oceans, which were very different from what oceans are now, would have formed a "hot dilute soup". In this soup, organic compounds, the building blocks of life, could have formed. This idea was called biopoiesis, the process of living matter evolving from self-replicating but nonliving molecules. 
There is almost no geological record from before 3.8 billion years ago. The environment that existed in the Hadean era was hostile to life, but how much so is not known. There was a time, between 3.8 and 4.1 billion years ago, which is known as the Late Heavy Bombardment. It is so named because many lunar craters are thought to have formed then. The situation on other planets, such as Earth, Venus, Mercury and Mars must have been similar. These impacts would likely sterilize the Earth (kill all life), if it existed at that time. 
Several people have suggested that the chemicals in the cell give clues as to what the early seas must have been like. In 1926, Macallum noted that the inorganic composition of the cell cytosol dramatically differs from that of modern sea water: "the cell… has endowments transmitted from a past almost as remote as the origin of life on earth".  For example: "All cells contain much more potassium, phosphate, and transition metals than modern . oceans, lakes, or rivers".  "Under the anoxic, CO2-dominated primordial atmosphere, the chemistry of inland basins at geothermal fields would [be like the chemistry inside] modern cells". 
If life evolved in the deep ocean, near a hydrothermal vent, it could have originated as early as 4 to 4.2 billion years ago. If, on the other hand, life originated at the surface of the planet, a common opinion is it could only have done so between 3.5 and 4 billion years ago. 
Lazcano and Miller (1994) suggest that the pace of molecular evolution was dictated by the rate of recirculating water through mid-ocean submarine vents. Complete recirculation takes 10 million years, so any organic compounds produced by then would be altered or destroyed by temperatures exceeding 300 °C. They estimate that the development of a 100 kilobase genome of a DNA/protein primitive heterotroph into a 7000 gene filamentous cyanobacterium would have required only 7 million years. 
History of Earth's atmosphere Edit
Originally, the Earth's atmosphere had almost no free oxygen. It gradually changed to what it is today, over a very long time (see Great Oxygenation Event). The process began with cyanobacteria. They were the first organisms to make free oxygen by photosynthesis. Most organisms today need oxygen for their metabolism only a few can use other sources for respiration.  
So it is expected that the first proto-organisms were chemoautotrophs, and did not use aerobic respiration. They were anaerobic.
There is no "standard model" on how life started. Most accepted models are built on molecular biology and cell biology:
- Because there are the right conditions, some basic small molecules are created. These are called monomers of life. Amino acids are one type of these molecules. This was proved by the Miller–Urey experiment by Stanley L. Miller and Harold C. Urey in 1953, and we now know these basic building blocks are common throughout space. Early Earth would have had them all. , which can form lipid bilayers, a main component of the cell membrane. which might join up into random RNA molecules. This might have resulted in self-replicating ribozymes (RNA world hypothesis).
- Competition for substrates would select mini-proteins into enzymes. The ribosome is critical to protein synthesis in present-day cells, but we have no idea as to how it evolved.
- Early on, ribonucleic acids would have been catalysts, but later, nucleic acids are specialised for genomic use.
The origin of the basic biomolecules, while not settled, is less controversial than the significance and order of steps 2 and 3. The basic chemicals from which life is thought to have formed are:
Molecular oxygen (O2) and ozone (O3) were either rare or absent.
Three stages Edit
- Stage 1: The origin of biological monomers
- Stage 2: The origin of biological polymers
- Stage 3: The evolution from molecules to cells
Bernal suggested that evolution may have commenced early, some time between Stage 1 and 2.
There are three sources of organic molecules on the early Earth:
- organic synthesis by energy sources (such as ultraviolet light or electrical discharges).
- delivery by extraterrestrial objects such as carbonaceous meteorites (chondrites)
- organic synthesis driven by impact shocks.
Estimates of these sources suggest that the heavy bombardment before 3.5 billion years ago made available quantities of organics comparable to those produced by other energy sources. 
Miller's experiment and the primordial soup Edit
In 1953 a graduate student, Stanley Miller, and his professor, Harold Urey, performed an experiment that showed how organic molecules could have formed on early Earth from inorganic precursors.
The now-famous Miller–Urey experiment used a highly reduced mixture of gases – methane, ammonia and hydrogen – to form basic organic monomers, such as amino acids.  We do know now that for more than the first half of the Earth's history its atmosphere had almost no oxygen.
Fox's experiments Edit
In the 1950s and 1960s, Sidney W. Fox studied the spontaneous formation of peptide structures under conditions that might have existed early in Earth's history. He demonstrated that amino acids could by itself form small peptides. These amino acids and small peptides could be encouraged to form closed spherical membranes, called microspheres. 
Some scientists have suggested special conditions which could make cell synthesis easier.
Clay world Edit
A clay model for the origin of life was suggested by A. Graham Cairns-Smith. Clay theory suggests complex organic molecules arose gradually on a pre-existing non-organic platform, namely, silicate crystals in solution. 
Deep-hot biosphere model Edit
In the 1970s, Thomas Gold proposed the theory that life first developed not on the surface of the Earth, but several kilometers below the surface. The discovery in the late 1990s of nanobes (filamental structures that are smaller than bacteria, but that may contain DNA in deep rocks)  might support Gold's theory.
It is now reasonably well established that microbial life is plentiful at shallow depths in the Earth (up to five kilometers below the surface)  in the form of extremophile archaea, rather than the better-known eubacteria (which live in more accessible conditions).
Gold asserted that a trickle of food from a deep, unreachable, source is needed for survival because life arising in a puddle of organic material is likely to consume all of its food and become extinct. Gold's theory was that the flow of food is due to out-gassing of primordial methane from the Earth's mantle.
Self-organization and replication Edit
Self-organization and self-replication are the hallmark of living systems. Non-living molecules sometimes show those features under proper conditions. For example, Martin and Russel showed that cell membranes separating contents from the environment and self-organization of self-contained redox reactions are the most conserved attributes of living things. They argue that inorganic matter like that would be life's most likely last common ancestor. 
RNA world hypothesis Edit
In this hypothesis, RNA is said to work both as an enzyme and as a container of genes. Later, DNA took over its genetic role.
The RNA world hypothesis proposes that life based on ribonucleic acid (RNA) pre-dates the current world of life based on deoxyribonucleic acid (DNA), RNA and proteins. RNA is able both to store genetic information, like DNA, and to catalyze chemical reactions, like an enzyme. It may have supported pre-cellular life and been a major step towards cellular life.
There are some pieces of evidence which support this idea:
- There are some RNAs which work as enzymes.
- Some viruses use RNA for heredity.
- Many of the most fundamental parts of the cell (those that evolve the slowest) require RNA.
Metabolism and proteins Edit
This idea suggests that proteins worked as enzymes first, producing metabolism. After that DNA and RNA began to work as containers of genes.
This idea also has some evidences which supports this.
- as enzyme is essential for today's lives.
- Some amino acids are formed from more basic chemicals in the Miller-Urey experiment. Some deny this idea because Proteins cannot copy themselves.
In this scheme membranes made of lipid bilayers occur early on. Once organic chemicals are enclosed, more complex biochemistry is then possible. 
This is the idea suggested by Arrhenius,   and developed by Fred Hoyle,  that life developed elsewhere in the universe and arrived on Earth in the form of spores. This is not a theory of how life began, but a theory of how it might have spread. It may have spread, for example, by meteorites. 
Some propose that early Mars was a better place to start life than was the early Earth. The molecules which combined to form genetic material are more complex than the "primordial soup" of organic (carbon-based) chemicals that existed on Earth four billion years ago. If RNA was the first genetic material, then minerals containing boron and molybdenum could assist in its formation. These minerals were much more common on Mars than on Earth. 
In Christianity, some people reject the idea of evolution. They believe that the Earth is only a few thousand years old. This is known as Young Earth Creationism. However, the Bible does not explicitly state the age of the Earth, only that 'In the beginning, God created the heavens and the earth.' (Genesis 1:1)
God is portrayed as the creator of all things, and the originator of life on Earth (Genesis 1 & 2).
Theories of the origin of life
All cultures have developed stories to explain the origin of life. During the medieval period, for example, European scholars argued that small creatures such as insects, amphibians, and mice, appeared by spontaneous generation — natural self-assembly of nonliving ingredients — in old clothes or piles of garbage. Italian physician Francesco Redi (1626 – 1698) challenged this belief in 1668, when he showed that maggots come from eggs laid by flies rather than forming spontaneously from the decaying matter in which they are found.
A series of experiments conducted in the 1860s by the French microbiologist Louis Pasteur (1822 – 1895) also helped to disprove the idea that life originated by spontaneous generation. Pasteur sterilized two containers, both of which contained a broth rich in nutrients. He exposed both containers to the air, but one had a trap in the form of a loop in a connecting tube, which prevented dust and other particles from reaching the broth. Bacteria and mold quickly grew in the open container and made its broth cloudy and rank, but the container with the trap remained sterile. Pasteur interpreted this experiment as indicating that microorganisms did not arise spontaneously in the open container, but were introduced by dust and other airborne contaminants.
Although Redi, Pasteur, and other scientists thoroughly disproved the theory of spontaneous generation as an explanation for the origin of present-day life on whatever scale, they raised a new question: If organisms can arise only from other organisms, how then did the first organism arise?
Charles Darwin (1809 – 1882), the famous English naturalist, suggested that life might have first occurred in “ some warm little pond ” rich in minerals and chemicals, and exposed to electricity and light. Darwin argued that once the first living beings appeared, all other creatures that have ever lived could have evolved from them. In other words, spontaneous generation did occur — but only a long time ago, when the first, minimally complex forms of life would have faced no competition from more-competent cells. Many of the laboratory experiments that would eventually be conducted to shed light on the origin of life have been variations on Darwin ’ s “ warm little pond. ” first, however, another influential suggestion regarding the origin of life was provided by Russian scientist Aleksandr Oparin (1894 – 1980) and English scientist J. B. S. Haldane (1892 – 1964). Oparin and Haldane suggested in the 1920s that the atmosphere of billions of years ago would have been very different from today ’ s. The modern atmosphere is about 79% nitrogen (N2) and 20.9% free oxygen (O2), with only trace quantities of other gases. Because of the presence of oxygen, which combines readily with many other substances, such an atmosphere is termed oxidizing. Oparin noted that oxygen interferes with the formation of organic compounds necessary for life by combining with their hydrogen atoms and reasoned that the atmosphere present when life began must have been a reducing atmosphere, which contained little or no oxygen but had high concentrations of gases that can react to provide hydrogen atoms to synthesize the compounds needed to create life. Oparin and Haldane suggested that this primordial, reducing atmosphere consisted of hydrogen (H2), ammonia (NH3), methane (CH4), and additional simple hydrocarbons (molecules consisting only of carbon and hydrogen atoms). Oxygen could not have been present in large quantities because it is chemically unstable, and is only maintained as a major ingredient of the atmosphere by the action of green plants and algae — that is, by life itself. Before life, Earth ’ s atmosphere could not have been strongly oxidizing.
According to this theory, energy for rearranging atoms and molecules into organic forms that promoted the genesis of life came from sunlight, lightning, and/or geothermal heat. This model of the early environment became especially popular among scientists after a U.S. graduate student of physics named Stanley Miller (1930 – ), then studying at the University of Chicago, designed an experiment to test it. In 1953, Miller filled a closed glass container with a mixture of the gases that Oparin and haldane suggested were in the ancient atmosphere. In the bottom of the container was a reservoir of boiling water, and above it an apparatus that caused electrical sparks to pass through the gas mixture. After one week of reaction, Miller found that amino acids and other organic chemicals had formed from the gases and water. In the years since Miller reported his results, other researchers have performed more sophisticated “ warm little pond ” experiments, and have been able to synthesize additional amino acids and even nucleic acids, the molecules that organize into RNA and DNA, which in turn encode the genetic information of organisms.
Subsequent research influenced by these experiments led many scientists to believe that the concentration of organic molecules in the primordial, nutrient-laden, warm “ ponds ” (which may have been tidal pools, puddles, shallow lakes, or deep-sea hot springs) increased progressively over time. Eventually more complex molecules formed, such as carbohydrates, lipids, proteins, and nucleic acids. The complexity gap between simple nucleic acids and self-replicating RNA or DNA is, however, large therefore, some scientists have theorized that assembly of more complex compounds from simpler ones may have occurred on the surface of oily drops floating on the water surface, or on the surfaces of minerals — objects whose atomic structure might have provided a template for stringing together nucleic acids and giving them a place to “ live ” until free-floating cells protected by lipid membranes could evolve.
However, some scientists believe that the young Earth ’ s surface was too inhospitable a place for life to have developed on its surface at all lacking O2, the atmosphere would also have lacked its present-day stratospheric layer of ozone (O3), which screens large quantities of harmful ultraviolet radiation from the surface. They believe that a more likely environment for abiogenesis (life from prelife) was in the vicinity of deep-sea vents, holes in the crust under the ocean from which hot, mineral-laden water flows.
Furthermore, many scientists today believe that the prelife atmosphere may not have been as strongly reducing as the one proposed by Oparin and Haldane and used in Miller ’ s experiment. They assert that volcanoes added carbon monoxide (CO), carbon dioxide (CO2), and nitrogen to the early atmosphere, which may even have contained traces of oxygen. Nevertheless, more recent experiments of the Miller type, run using a less reducing atmosphere, have also resulted in the synthesis of organic compounds. In fact, all 20 of the amino acids found in organisms have been created in the laboratory under experimental conditions designed to mimic what scientists believe the prelife Earth was like billions of years ago — whether using Miller ’ s model or its less-reducing competitors.
But in the absence of life, how did these amino acids link together into more complex compounds? Living cellular chemistry links amino acids together using specific enzymes to form particular proteins. An amino acid is any compound which contains at least one amino group ( – NH2) and one carboxyl group ( – COOH). When amino acids are linked, a hydrogen molecule and a hydroxyl group (OH) are removed from each amino acids, which then link up into a protein chain, while the hydrogen and hydroxyl link up as a water molecule (H + OH = h2O). Without enzymes, amino acids do not link up in this way — or, as a biochemist might describe it, polymerization does not proceed.
How, then, could amino acids have joined to form proteins without the proteins termed enzymes to help them? One possibility is that amino acids may have joined together on hot sand, clay, or other minerals. Laboratory experiments have shown that amino acids and other organic building blocks of larger molecules, called polymers, will join together if dilute solutions of them are dripped onto warm sand, clay, or other minerals. The larger molecules formed in this way have been named proteinoids. It is easy to imagine some version of Darwin ’ s “ warm little pond ” — a soup of spontaneously-formed amino acids — splashing onto hot volcanic rocks. Clay and iron pyrite have particularly favorable properties making them good “ platforms ” for the formation of larger molecules from smaller building blocks. One recently proposed theory of the origin of life suggests that tiny (= ̃ .01-mm diameter) hollows in iron sulfide minerals, such as are deposited in the vicinity of deep-sea hot springs, might have incubated the earliest life chemistry. Iron sulfide catalyzes the formation of organic molecules, and is used by some modern bacteria for this purpose. Sheltered in tiny iron-sulfide caverns, prebiotic chemistry might have developed at leisure, leaving this protected environment only after evolving a protective lipid membrane. This theory, however, like all theories of the origin of life, has its scientific opponents, and awaits the production of confirming or disconfirming laboratory evidence.
Proteinoids produced in laboratories can cluster together into droplets that separate, and that may protect their components from degrading influences of the surrounding environment. These droplets are like extremely simple cells, although they cannot reproduce. Such droplets are called microspheres. When fats (i.e., lipids) are present, the microspheres that form are even more cell-like. If a mixture of linked amino acids called polypeptides, sugars called polysaccharides, and nucleic acids is shaken, droplets called coacervates will form. All of these kinds of droplets are called protobionts, and they may represent a stage in the genesis of cellular life.
The formation of amino acids and other organic compounds is presumed to have been a necessary step in the genesis of life it is certain, at least, that somewhere along the line all life became dependent on DNA and RNA for reproduction. Scientists thus presume that the first self-replicating molecules were similar to the nucleic acids of modern organisms. (These early molecular systems need not have been as complex as the self-replicating systems that comprise modern cells. Researchers have recently shown, by deleting genes, that even the genetically simplest bacteria alive today can reproduce with much less than their full natural complement of DNA.) Once molecules that could self-replicate were formed, the process of evolution would account for the subsequent development of life. The particular molecules best adapted to the local environmental conditions would have duplicated themselves more efficiently than competing molecules. Eventually, primitive cells appeared perhaps coacervates or other protobionts played a role at this stage in the genesis of life. Once cells became established, evolution by natural selection could have resulted in the development of all of the life-forms that have ever existed on Earth.
When it addresses this question, evolutionary theory claims that life started with a cell that formed by chance. According to this scenario, four billion years ago various chemical compounds underwent a reaction in the primordial atmosphere on the earth in which the effects of thunderbolts and atmospheric pressure led to the formation of the first living cell.
The first thing that must be said is that the claim that nonliving materials can come together to form life is an unscientific one that has not been verified by any experiment or observation. Life is only generated from life. Each living cell is formed by the replication of another cell. No one in the world has ever succeeded in forming a living cell by bringing inanimate materials together, not even in the most advanced laboratories.
The theory of evolution claims that a living cell-which cannot be produced even when all the power of the human intellect, knowledge and technology are brought to bear-nevertheless managed to form by chance under primordial conditions on the earth. In the following pages, we will examine why this claim is contrary to the most basic principles of science and reason.
An Example of the Logic of “Chance”
If one believes that a living cell can come into existence by chance, then there is nothing to prevent one from believing a similar story that we will relate below. It is the story of a town.
One day, a lump of clay, pressed between the rocks in a barren land, becomes wet after it rains. The wet clay dries and hardens when the sun rises, and takes on a stiff, resistant form. Afterwards, these rocks, which also served as a mould, are somehow smashed into pieces, and then a neat, well shaped, and strong brick appears. This brick waits under the same natural conditions for years for a similar brick to be formed. This goes on until hundreds and thousands of the same bricks have been formed in the same place. However, by chance, none of the bricks that were previously formed are damaged. Although exposed to storms, rain, wind, scorching sun, and freezing cold for thousands of years, the bricks do not crack, break up, or get dragged away, but wait there in the same place with the same determination for other bricks to form.
When the number of bricks is adequate, they erect a building by being arranged sideways and on top of each other, having been randomly dragged along by the effects of natural conditions such as winds, storms, or tornadoes. Meanwhile, materials such as cement or soil mixtures form under “natural conditions,” with perfect timing, and creep between the bricks to clamp them to each other. While all this is happening, iron ore under the ground is shaped under “natural conditions” and lays the foundations of a building that is to be formed with these bricks. At the end of this process, a complete building rises with all its materials, carpentry, and installations intact.
Of course, a building does not only consist of foundations, bricks, and cement. How, then, are the other missing materials to be obtained? The answer is simple: all kinds of materials that are needed for the construction of the building exist in the earth on which it is erected. Silicon for the glass, copper for the electric cables, iron for the columns, beams, water pipes, etc. all exist under the ground in abundant quantities. It takes only the skill of “natural conditions” to shape and place these materials inside the building. All the installations, carpentry, and accessories are placed among the bricks with the help of the blowing wind, rain, and earthquakes. Everything has gone so well that the bricks are arranged so as to leave the necessary window spaces as if they knew that something called glass would be formed later on by natural conditions. Moreover, they have not forgotten to leave some space to allow the installation of water, electricity and heating systems, which are also later to be formed by chance. Everything has gone so well that “coincidences” and “natural conditions” produce a perfect design.
If you have managed to sustain your belief in this story so far, then you should have no trouble surmising how the town’s other buildings, plants, highways, sidewalks, substructures, communications, and transportation systems came about. If you possess technical knowledge and are fairly conversant with the subject, you can even write an extremely “scientific” book of a few volumes stating your theories about “the evolutionary process of a sewage system and its uniformity with the present structures.” You may well be honored with academic awards for your clever studies, and may consider yourself a genius, shedding light on the nature of humanity.
The theory of evolution, which claims that life came into existence by chance, is no less absurd than our story, for, with all its operational systems, and systems of communication, transportation and management, a cell is no less complex than a city. In his book Evolution: A Theory in Crisis, the molecular biologist Michael Denton discusses the complex structure of the cell:
To grasp the reality of life as it has been revealed by molecular biology, we must magnify a cell a thousand million times until it is twenty kilometers in diameter and resembles a giant airship large enough to cover a great city like London or New York. What we would then see would be an object of unparalleled complexity and adaptive design. On the surface of the cell we would see millions of openings, like the port holes of a vast space ship, opening and closing to allow a continual stream of materials to flow in and out. If we were to enter one of these openings we would find ourselves in a world of supreme technology and bewildering complexity… Is it really credible that random processes could have constructed a reality, the smallest element of which-a functional protein or gene-is complex beyond our own creative capacities, a reality which is the very antithesis of chance, which excels in every sense anything produced by the intelligence of man?237
The Complex Structure and Systems in the Cell
The complex structure of the living cell was unknown in Darwin’s day and at the time, ascribing life to “coincidences and natural conditions” was thought by evolutionists to be convincing enough. Darwin had proposed that the first cell could easily have formed “in some warm little pond. One of Darwin’s supporters, the German biologist Ernst Haeckel, examined under the microscope a mixture of mud removed from the sea bed by a research ship and claimed that this was a nonliving substance that turned into a living one. This so-called “mud that comes to life,” known as Bathybius haeckelii (“Haeckel’s mud from the depths”), is an indication of just how simple a thing life was thought to be by the founders of the theory of evolution.
The technology of the twentieth century has delved into the tiniest particles of life, and has revealed that the cell is the most complex system mankind has ever confronted. Today we know that the cell contains power stations producing the energy to be used by the cell, factories manufacturing the enzymes and hormones essential for life, a databank where all the necessary information about all products to be produced is recorded, complex transportation systems and pipelines for carrying raw materials and products from one place to another, advanced laboratories and refineries for breaking down external raw materials into their useable parts, and specialized cell membrane proteins to control the incoming and outgoing materials. And these constitute only a small part of this incredibly complex system.
W. H. Thorpe, an evolutionist scientist, acknowledges that “The most elementary type of cell constitutes a ‘mechanism’ unimaginably more complex than any machine yet thought up, let alone constructed, by man.
A cell is so complex that even the high level of technology attained today cannot produce one. No effort to create an artificial cell has ever met with success. Indeed, all attempts to do so have been abandoned.
The theory of evolution claims that this system-which mankind, with all the intelligence, knowledge and technology at its disposal, cannot succeed in reproducing-came into existence “by chance” under the conditions of the primordial earth. Actually, the probability of forming a cell by chance is about the same as that of producing a perfect copy of a book following an explosion in a printing house.
The English mathematician and astronomer Sir Fred Hoyle made a similar comparison in an interview published in Nature magazine on November 12, 1981. Although an evolutionist himself, Hoyle stated that the chance that higher life forms might have emerged in this way is comparable to the chance that a tornado sweeping through a junk-yard might assemble a Boeing 747 from the materials therein.240 This means that it is not possible for the cell to have come into being by chance, and therefore it must definitely have been “created.”
One of the basic reasons why the theory of evolution cannot explain how the cell came into existence is the “irreducible complexity” in it. A living cell maintains itself with the harmonious co-operation of many organelles. If only one of these organelles fails to function, the cell cannot remain alive. The cell does not have the chance to wait for unconscious mechanisms like natural selection or mutation to permit it to develop. Thus, the first cell on earth was necessarily a complete cell possessing all the required organelles and functions, and this definitely means that this cell had to have been created.
The Problem of the Origin of Proteins
So much for the cell, but evolution fails even to account for the building-blocks of a cell. The formation, under natural conditions, of just one single protein out of the thousands of complex protein molecules making up the cell is impossible.
Proteins are giant molecules consisting of smaller units called amino acids that are arranged in a particular sequence in certain quantities and structures. These units constitute the building blocks of a living protein. The simplest protein is composed of 50 amino acids, but there are some that contain thousands.
The crucial point is this. The absence, addition, or replacement of a single amino acid in the structure of a protein causes the protein to become a useless molecular heap. Every amino acid has to be in the right place and in the right order. The theory of evolution, which claims that life emerged as a result of chance, is quite helpless in the face of this order, since it is too wondrous to be explained by coincidence. (Furthermore, the theory cannot even substantiate the claim of the accidental formation of amino acids, as will be discussed later.)
The fact that it is quite impossible for the functional structure of proteins to come about by chance can easily be observed even by simple probability calculations that anybody can understand.
For instance, an average-sized protein molecule composed of 288 amino acids, and contains twelve different types of amino acids can be arranged in 10300 different ways. (This is an astronomically huge number, consisting of 1 followed by 300 zeros.) Of all of these possible sequences, only one forms the desired protein molecule. The rest of them are amino-acid chains that are either totally useless, or else potentially harmful to living things.
In other words, the probability of the formation of only one protein molecule is in 10 300 .” The probability of this ” actually occurring is practically nil. (In practice, probabilities smaller than 1 over 10 50 are thought of as “zero probability”).
Furthermore, a protein molecule of 288 amino acids is a rather modest one compared with some giant protein molecules consisting of thousands of amino acids. When we apply similar probability calculations to these giant protein molecules, we see that even the word “impossible” is insufficient to describe the true situation.
When we proceed one step further in the evolutionary scheme of life, we observe that one single protein means nothing by itself. One of the smallest bacteria ever discovered, Mycoplasma hominis H39, contains 600 types of proteins. In this case, we would have to repeat the probability calculations we have made above for one protein for each of these 600 different types of proteins. The result beggars even the concept of impossibility.
Some people reading these lines who have so far accepted the theory of evolution as a scientific explanation may suspect that these numbers are exaggerated and do not reflect the true facts. That is not the case: these are definite and concrete facts. No evolutionist can object to these numbers.
This situation is in fact acknowledged by many evolutionists. For example, Harold F. Blum, a prominent evolutionist scientist, states that “The spontaneous formation of a polypeptide of the size of the smallest known proteins seems beyond all probability.”241
Evolutionists claim that molecular evolution took place over a very long period of time and that this made the impossible possible. Nevertheless, no matter how long the given period may be, it is not possible for amino acids to form proteins by chance. William Stokes, an American geologist, admits this fact in his book Essentials of Earth History, writing that the probability is so small “that it would not occur during billions of years on billions of planets, each covered by a blanket of concentrated watery solution of the necessary amino acids.
So what does all this mean? Perry Reeves, a professor of chemistry, answers the question:
When one examines the vast number of possible structures that could result from a simple random combination of amino acids in an evaporating primordial pond, it is mind-boggling to believe that life could have originated in this way. It is more plausible that a Great Builder with a master plan would be required for such a task.243
If the coincidental formation of even one of these proteins is impossible, it is billions of times “more impossible” for some one million of those proteins to come together by chance and make up a complete human cell. What is more, by no means does a cell consist of a mere heap of proteins. In addition to the proteins, a cell also includes nucleic acids, carbohydrates, lipids, vitamins, and many other chemicals such as electrolytes arranged in a specific proportion, equilibrium, and design in terms of both structure and function. Each of these elements functions as a building block or co-molecule in various organelles.
Robert Shapiro, a professor of chemistry at New York University and a DNA expert, calculated the probability of the coincidental formation of the 2000 types of proteins found in a single bacterium (There are 200,000 different types of proteins in a human cell.) The number that was found was 1 over 10 40000 .244 (This is an incredible number obtained by putting 40,000 zeros after the 1)
A professor of applied mathematics and astronomy from University College Cardiff, Wales, Chandra Wickramasinghe, comments:
The likelihood of the spontaneous formation of life from inanimate matter is one to a number with 40,000 noughts after it… It is big enough to bury Darwin and the whole theory of evolution. There was no primeval soup, neither on this planet nor on any other, and if the beginnings of life were not random, they must therefore have been the product of purposeful intelligence.245
Sir Fred Hoyle comments on these implausible numbers:
Indeed, such a theory (that life was assembled by an intelligence) is so obvious that one wonders why it is not widely accepted as being self-evident. The reasons are psychological rather than scientific.246
An article published in the January 1999 issue of Science News revealed that no explanation had yet been found for how amino acids could turn into proteins:
.no one has ever satisfactorily explained how the widely distributed ingredients linked up into proteins. Presumed conditions of primordial Earth would have driven the amino acids toward lonely isolation.247
Let us now examine in detail why the evolutionist scenario regarding the formation of proteins is impossible.
Even the correct sequence of the right amino acids is still not enough for the formation of a functional protein molecule. In addition to these requirements, each of the 20 different types of amino acids present in the composition of proteins must be left-handed. There are two different types of amino acids-as of all organic molecules-called “left-handed” and “right-handed.” The difference between them is the mirror-symmetry between their three dimensional structures, which is similar to that of a person’s right and left hands.The same protein’s left- (L) and right- (D) handed isomers. The proteins in living creatures consist only of left-handed amino acids.
Amino acids of either of these two types can easily bond with one another. But one astonishing fact that has been revealed by research is that all the proteins in plants and animals on this planet, from the simplest organism to the most complex, are made up of left-handed amino acids. If even a single right-handed amino acid gets attached to the structure of a protein, the protein is rendered useless. In a series of experiments, surprisingly, bacteria that were exposed to right-handed amino acids immediately destroyed them. In some cases, they produced usable left-handed amino acids from the fractured components.
Let us for an instant suppose that life came about by chance as evolutionists claim it did. In this case, the right- and left-handed amino acids that were generated by chance should be present in roughly equal proportions in nature. Therefore, all living things should have both right- and left-handed amino acids in their constitution, because chemically it is possible for amino acids of both types to combine with each other. However, as we know, in the real world the proteins existing in all living organisms are made up only of left-handed amino acids.
The question of how proteins can pick out only the left-handed ones from among all amino acids, and how not even a single right-handed amino acid gets involved in the life process, is a problem that still baffles evolutionists. Such a specific and conscious selection constitutes one of the greatest impasses facing the theory of evolution.
Moreover, this characteristic of proteins makes the problem facing evolutionists with respect to “chance” even worse. In order for a “meaningful” protein to be generated, it is not enough for the amino acids to be present in a particular number and sequence, and to be combined together in the right three-dimensional design. Additionally, all these amino acids have to be left-handed: not even one of them can be right-handed. Yet there is no natural selection mechanism which can identify that a right-handed amino acid has been added to the sequence and recognize that it must therefore be removed from the chain. This situation once more eliminates for good the possibility of coincidence and chance.
The Britannica Science Encyclopaedia, which is an outspoken defender of evolution, states that the amino acids of all living organisms on earth, and the building blocks of complex polymers such as proteins, have the same left-handed asymmetry. It adds that this is tantamount to tossing a coin a million times and always getting heads. The same encyclopaedia states that it is impossible to understand why molecules become left-handed or right-handed, and that this choice is fascinatingly related to the origin of life on earth.248
If a coin always turns up heads when tossed a million times, is it more logical to attribute that to chance, or else to accept that there is conscious intervention going on? The answer should be obvious. However, obvious though it may be, evolutionists still take refuge in coincidence, simply because they do not want to accept the existence of conscious intervention.
A situation similar to the left-handedness of amino acids also exists with respect to nucleotides, the smallest units of the nucleic acids, DNA and RNA. In contrast to proteins, in which only left-handed amino acids are chosen, in the case of the nucleic acids, the preferred forms of their nucleotide components are always right-handed. This is another fact that can never be explained by chance.
In conclusion, it is proven beyond a shadow of a doubt by the probabilities we have examined that the origin of life cannot be explained by chance. If we attempt to calculate the probability of an average-sized protein consisting of 400 amino acids being selected only from left-handed amino acids, we come up with a probability of 1 in 2 400 , or 10 120 . Just for a comparison, let us remember that the number of electrons in the universe is estimated at 1079, which although vast, is a much smaller number. The probability of these amino acids forming the required sequence and functional form would generate much larger numbers. If we add these probabilities to each other, and if we go on to work out the probabilities of even higher numbers and types of proteins, the calculations become inconceivable.
The Indispensability of the Peptide Link
The difficulties the theory of evolution is unable to overcome with regard to the development of a single protein are not limited to those we have recounted so far. It is not enough for amino acids to be arranged in the correct numbers, sequences, and required three-dimensional structures. The formation of a protein also requires that amino acid molecules with more than one arm be linked to each other only in certain ways. Such a bond is called a “peptide bond.” Amino acids can make different bonds with each other but proteins are made up of those-and only those-amino acids which are joined by peptide bonds.
A comparison will clarify this point. Suppose that all the parts of a car were complete and correctly assembled, with the sole exception that one of the wheels was fastened in place not with the usual nuts and bolts, but with a piece of wire, in such a way that its hub faced the ground. It would be impossible for such a car to move even the shortest distance, no matter how complex its technology or how powerful its engine. At first glance, everything would seem to be in the right place, but the faulty attachment of even one wheel would make the entire car useless. In the same way, in a protein molecule the joining of even one amino acid to another with a bond other than a peptide bond would make the entire molecule useless.
Research has shown that amino acids combining at random combine with a peptide bond only 50 percent of the time, and that the rest of the time different bonds that are not present in proteins emerge. To function properly, each amino acid making up a protein must be joined to others only with a peptide bond, in the same way that it likewise must be chosen only from among left-handed forms.
The probability of this happening is the same as the probability of each protein’s being left-handed. That is, when we consider a protein made up of 400 amino acids, the probability of all amino acids combining among themselves with only peptide bonds is 1 in 2 399 .
If we add together the three probabilities (that of amino acids being laid out correctly, that of their all being left-handed, and that of their all being joined by peptide links), then we come face to face with the astronomical figure of 1 in 10 950 . This is a probability only on paper. Practically speaking, there is zero chance of its actually happening. As we saw earlier, in mathematics, a probability smaller than 1 in 10 50 is statistically considered to have a “zero” probability of occurring.
Even if we suppose that amino acids have combined and decomposed by a “trial and error” method, without losing any time since the formation of the earth, in order to form a single protein molecule, the time that would be required for something with a probability of 10 950 to happen would still hugely exceed the estimated age of the earth.
The conclusion to be drawn from all this is that evolution falls into a terrible abyss of improbability even when it comes to the formation of a single protein.
One of the foremost proponents of the theory of evolution, Professor Richard Dawkins, states the impossibility the theory has fallen into in these terms:
So the sort of lucky event we are looking at could be so wildly improbable that the chances of its happening, somewhere in the universe, could be as low as one in a billion billion billion in any one year. If it did happen on only one planet, anywhere in the universe, that planet has to be our planet-because here we are talking about it.249
This admission by one of evolution’s foremost authorities clearly reflects the logical muddle the theory of evolution is built on. The above statements in Dawkins’s book Climbing Mount Improbable are a striking example of circular reasoning which actually explains nothing: “If we are here, then that means that evolution happened.”
As we have seen, even the most prominent of the proponents of evolution confess that the theory is buried in impossibility when it comes to accounting for the first stage of life. But how interesting it is that, rather than accept the complete unreality of the theory they maintain, they prefer to cling to evolution in a dogmatic manner! This is a completely ideological fixation.
Is There a Trial-and-Error Mechanism in Nature?
Finally, we may conclude with a very important point in relation to the basic logic of probability calculations, of which we have already seen some examples. We indicated that the probability calculations made above reach astronomical levels, and that these astronomical odds have no chance of actually happening. However, there is a much more important and damaging fact facing evolutionists here. This is that under natural conditions, no period of trial and error can even start, despite the astronomical odds, because there is no trial-and-error mechanism in nature from which proteins could emerge.
The calculations we gave above to demonstrate the probability of the formation of a protein molecule with 500 amino acids are valid only for an ideal trial-and-error environment, which does not actually exist in real life. That is, the probability of obtaining a useful protein is ” in 10 950 only if we suppose that there exists an imaginary mechanism in which an invisible hand joins 500 amino acids at random and then, seeing that this is not the right combination, disentangles them one by one, and arranges them again in a different order, and so on. In each trial, the amino acids would have to be separated one by one, and arranged in a new order. The synthesis should be stopped after the 500th amino acid has been added, and it must be ensured that not even one extra amino acid is involved. The trial should then be stopped to see whether or not a functional protein has yet been formed, and, in the event of failure, everything should be split up again and then tested for another sequence. Additionally, in each trial, not even one extraneous substance should be allowed to become involved. It is also imperative that the chain formed during the trial should not be separated and destroyed before reaching the 499 th link. These conditions mean that the probabilities we have mentioned above can only operate in a controlled environment where there is a conscious mechanism directing the beginning, the end, and each intermediate stage of the process, and where only “the selection of the amino acids” is left to chance. It is clearly impossible for such an environment to exist under natural conditions. Therefore the formation of a protein in the natural environment is logically and technically impossible.
Since some people are unable to take a broad view of these matters, but approach them from a superficial viewpoint and assume protein formation to be a simple chemical reaction, they may make unrealistic deductions such as “amino acids combine by way of reaction and then form proteins.” However, accidental chemical reactions taking place in a nonliving structure can only lead to simple and primitive changes. The number of these is predetermined and limited. For a somewhat more complex chemical material, huge factories, chemical plants, and laboratories have to be involved. Medicines and many other chemical materials that we use in our daily life are made in just this way. Proteins have much more complex structures than these chemicals produced by industry. Therefore, it is impossible for proteins, each of which is a wonder of design and engineering, in which every part takes its place in a fixed order, to originate as a result of haphazard chemical reactions.
Let us for a minute put aside all the impossibilities we have described so far, and suppose that a useful protein molecule still evolved spontaneously “by accident.” Even so, evolution again has no answers, because in order for this protein to survive, it would need to be isolated from its natural habitat and be protected under very special conditions. Otherwise, it would either disintegrate from exposure to natural conditions on earth, or else join with other acids, amino acids, or chemical compounds, thereby losing its particular properties and turning into a totally different and useless substance.
What we have been discussing so far is the impossibility of just one protein’s coming about by chance. However, in the human body alone there are some 100,000 proteins functioning. Furthermore, there are about 1.5 million species named, and another 10 million are believed to exist. Although many similar proteins are used in many life forms, it is estimated that there must be 100 million or more types of protein in the plant and animal worlds. And the millions of species which have already become extinct are not included in this calculation. In other words, hundreds of millions of protein codes have existed in the world. If one considers that not even one protein can be explained by chance, it is clear what the existence of hundreds of millions of different proteins must mean.
Bearing this truth in mind, it can clearly be understood that such concepts as “coincidence” and “chance” have nothing to do with the existence of living things.
The Evolutionary Argument about the Origin of Life
Above all, there is one important point to take into consideration: If any one step in the evolutionary process is proven to be impossible, this is sufficient to prove that the whole theory is totally false and invalid. For instance, by proving that the haphazard formation of proteins is impossible, all other claims regarding the subsequent steps of evolution are also refuted. After this, it becomes meaningless to take some human and ape skulls and engage in speculation about them.
How living organisms came into existence out of nonliving matter was an issue that evolutionists did not even want to mention for a long time. However, this question, which had constantly been avoided, eventually had to be addressed, and attempts were made to settle it with a series of experiments in the second quarter of the twentieth century.
The main question was: How could the first living cell have appeared in the primordial atmosphere on the earth? In other words, what kind of explanation could evolutionists offer?
The first person to take the matter in hand was the Russian biologist Alexander I. Oparin, the founder of the concept of “chemical evolution.” Despite all his theoretical studies, Oparin was unable to produce any results to shed light on the origin of life. He says the following in his book The Origin of Life, published in 1936:
Unfortunately, however, the problem of the origin of the cell is perhaps the most obscure point in the whole study of the evolution of organisms.250
Since Oparin, evolutionists have performed countless experiments, conducted research, and made observations to prove that a cell could have been formed by chance. However, every such attempt only made the complex design of the cell clearer, and thus refuted the evolutionists’ hypotheses even more. Professor Klaus Dose, the president of the Institute of Biochemistry at the University of Johannes Gutenberg, states:
More than 30 years of experimentation on the origin of life in the fields of chemical and molecular evolution have led to a better perception of the immensity of the problem of the origin of life on earth rather than to its solution. At present all discussions on principal theories and experiments in the field either end in stalemate or in a confession of ignorance.251
In his book The End of Science, the evolutionary science writer John Horgan says of the origin of life, “This is by far the weakest strut of the chassis of modern biology.
The following statement by the geochemist Jeffrey Bada, from the San Diego-based Scripps Institute, makes the helplessness of evolutionists clear:
Today, as we leave the twentieth century, we still face the biggest unsolved problem that we had when we entered the twentieth century: How did life originate on Earth?253
Let us now look at the details of the theory of evolution’s “biggest unsolved problem”. The first subject we have to consider is the famous Miller experiment.
The most generally respected study on the origin of life is the Miller experiment conducted by the American researcher Stanley Miller in 1953. (The experiment is also known as the “Urey-Miller experiment” because of the contribution of Miller’s instructor at the University of Chicago, Harold Urey.) This experiment is the only “evidence” evolutionists have with which to allegedly prove the “chemical evolution thesis” they advance it as the first stage of the supposed evolutionary process leading to life. Although nearly half a century has passed, and great technological advances have been made, nobody has made any further progress. In spite of this, Miller’s experiment is still taught in textbooks as the evolutionary explanation of the earliest generation of living things. That is because, aware of the fact that such studies do not support, but rather actually refute, their thesis, evolutionist researchers deliberately avoid embarking on such experiments.
Stanley Miller’s aim was to demonstrate by means of an experiment that amino acids, the building blocks of proteins, could have come into existence “by chance” on the lifeless earth billions of years ago. In his experiment, Miller used a gas mixture that he assumed to have existed on the primordial earth (but which later proved unrealistic), composed of ammonia, methane, hydrogen, and water vapor. Since these gases would not react with each other under natural conditions, he added energy to the mixture to start a reaction among them. Supposing that this energy could have come from lightning in the primordial atmosphere, he used an electric current for this purpose.
Miller heated this gas mixture at 100°C for a week and added the electrical current. At the end of the week, Miller analyzed the chemicals which had formed at the bottom of the jar, and observed that three out of the 20 amino acids which constitute the basic elements of proteins had been synthesized.
This experiment aroused great excitement among evolutionists, and was promoted as an outstanding success. Moreover, in a state of intoxicated euphoria, various publications carried headlines such as “Miller creates life.” However, what Miller had managed to synthesize was only a few inanimate molecules.
Encouraged by this experiment, evolutionists immediately produced new scenarios. Stages following the development of amino acids were hurriedly hypothesized. Supposedly, amino acids had later united in the correct sequences by accident to form proteins. Some of these proteins which emerged by chance formed themselves into cell membrane-like structures which “somehow” came into existence and formed a primitive cell. These cells then supposedly came together over time to form multicellular living organisms.
However, Miller’s experiment has since proven to be false in many respects.
Four Facts That Invalidate Miller’s Experiment
Miller’s experiment sought to prove that amino acids could form on their own in primordial earth-like conditions, but it contains inconsistencies in a number of areas:
1- By using a mechanism called a “cold trap,” Miller isolated the amino acids from the environment as soon as they were formed. Had he not done so, the conditions in the environment in which the amino acids were formed would immediately have destroyed these molecules.
Doubtless, this kind of conscious isolation mechanism did not exist on the primordial earth. Without such a mechanism, even if one amino acid were obtained, it would immediately have been destroyed. The chemist Richard Bliss expresses this contradiction by observing that “Actually, without this trap, the chemical products, would have been destroyed by the energy source. And, sure enough, in his previous experiments, Miller had been unable to make even one single amino acid using the same materials without the cold trap mechanism.
2- The primordial atmosphere that Miller attempted to simulate in his experiment was not realistic. In the 1980s, scientists agreed that nitrogen and carbon dioxide should have been used in this artificial environment instead of methane and ammonia.
So why did Miller insist on these gases? The answer is simple: without ammonia, it was impossible to synthesize any amino acid. Kevin Mc Kean talks about this in an article published in Discover magazine:
Miller and Urey imitated the ancient atmosphere on the Earth with a mixture of methane and ammonia. …However in the latest studies, it has been understood that the Earth was very hot at those times, and that it was composed of melted nickel and iron. Therefore, the chemical atmosphere of that time should have been formed mostly of nitrogen (N2), carbon dioxide (CO2) and water vapour (H2O). However these are not as appropriate as methane and ammonia for the production of organic molecules.255
The artificial atmosphere created by Miller in his experiment actually bore not the slightest resemblance to the primitive atmosphere on earth.
The American scientists J. P. Ferris and C. T. Chen repeated Miller’s experiment with an atmospheric environment that contained carbon dioxide, hydrogen, nitrogen, and water vapor, and were unable to obtain even a single amino acid molecule.256
3- Another important point that invalidates Miller’s experiment is that there was enough oxygen to destroy all the amino acids in the atmosphere at the time when they were thought to have been formed. This fact, overlooked by Miller, is revealed by the traces of oxidized iron found in rocks that are estimated to be 3.5 billion years old.257
There are other findings showing that the amount of oxygen in the atmosphere at that time was much higher than originally claimed by evolutionists. Studies also show that the amount of ultraviolet radiation to which the earth was then exposed was 10,000 times more than evolutionists’ estimates. This intense radiation would unavoidably have freed oxygen by decomposing the water vapor and carbon dioxide in the atmosphere.
This situation completely negates Miller’s experiment, in which oxygen was completely neglected. If oxygen had been used in the experiment, methane would have decomposed into carbon dioxide and water, and ammonia into nitrogen and water. On the other hand, in an environment where there was no oxygen, there would be no ozone layer either therefore, the amino acids would have immediately been destroyed, since they would have been exposed to the most intense ultraviolet rays without the protection of the ozone layer. In other words, with or without oxygen in the primordial world, the result would have been a deadly environment for the amino acids.
4- At the end of Miller’s experiment, many organic acids had also been formed with characteristics detrimental to the structure and function of living things. If the amino acids had not been isolated, and had been left in the same environment with these chemicals, their destruction or transformation into different compounds through chemical reactions would have been unavoidable.
Moreover, Miller’s experiment also produced right-handed amino acids.258 The existence of these amino acids refuted the theory even within its own terms, because right-handed amino acids cannot function in the composition of living organisms. To conclude, the circumstances in which amino acids were formed in Miller’s experiment were not suitable for life. In truth, this medium took the form of an acidic mixture destroying and oxidizing the useful molecules obtained.Today, Miller too accepts that his 1953 experiment was very far from explaining the origin of life.
All these facts point to one firm truth: Miller’s experiment cannot claim to have proved that living things formed by chance under primordial earth-like conditions. The whole experiment is nothing more than a deliberate and controlled laboratory experiment to synthesize amino acids. The amount and types of the gases used in the experiment were ideally determined to allow amino acids to originate. The amount of energy supplied to the system was neither too much nor too little, but arranged precisely to enable the necessary reactions to occur. The experimental apparatus was isolated, so that it would not allow the leaking of any harmful, destructive, or any other kind of elements to hinder the formation of amino acids. No elements, minerals or compounds that were likely to have been present on the primordial earth, but which would have changed the course of the reactions, were included in the experiment. Oxygen, which would have prevented the formation of amino acids because of oxidation, is only one of these destructive elements. Even under such ideal laboratory conditions, it was impossible for the amino acids produced to survive and avoid destruction without the “cold trap” mechanism.
In fact, by his experiment, Miller destroyed evolution’s claim that “life emerged as the result of unconscious coincidences.” That is because, if the experiment proves anything, it is that amino acids can only be produced in a controlled laboratory environment where all the conditions are specifically designed by conscious intervention.
Today, Miller’s experiment is totally disregarded even by evolutionist scientists. In the February 1998 issue of the famous evolutionist science journal Earth, the following statements appear in an article titled “Life’s Crucible”:
Geologist now think that the primordial atmosphere consisted mainly of carbon dioxide and nitrogen, gases that are less reactive than those used in the 1953 experiment. And even if Miller’s atmosphere could have existed, how do you get simple molecules such as amino acids to go through the necessary chemical changes that will convert them into more complicated compounds, or polymers, such as proteins? Miller himself throws up his hands at that part of the puzzle. “It’s a problem,” he sighs with exasperation. “How do you make polymers? That’s not so easy.
As seen, today even Miller himself has accepted that his experiment does not lead to an explanation of the origin of life. In the March 1998 issue of National Geographic, in an article titled “The Emergence of Life on Earth,” the following comments appear:
Many scientists now suspect that the early atmosphere was different to what Miller first supposed. They think it consisted of carbon dioxide and nitrogen rather than hydrogen, methane, and ammonia.
That’s bad news for chemists. When they try sparking carbon dioxide and nitrogen, they get a paltry amount of organic molecules – the equivalent of dissolving a drop of food colouring in a swimming pool of water. Scientists find it hard to imagine life emerging from such a diluted soup.260
In brief, neither Miller’s experiment, nor any other similar one that has been attempted, can answer the question of how life emerged on earth. All of the research that has been done shows that it is impossible for life to emerge by chance, and thus confirms that life is created. The reason evolutionists do not accept this obvious reality is their blind adherence to prejudices that are totally unscientific. Interestingly enough, Harold Urey, who organized the Miller experiment with his student Stanley Miller, made the following confession on this subject:
All of us who study the origin of life find that the more we look into it, the more we feel it is too complex to have evolved anywhere. We all believe as an article of faith that life evolved from dead matter on this planet. It is just that its complexity is so great, it is hard for us to imagine that it did.261
The Primordial Atmosphere and Proteins
Evolutionist sources use the Miller experiment, despite all of its inconsistencies, to try to gloss over the question of the origin of amino acids. By giving the impression that the issue has long since been resolved by that invalid experiment, they try to paper over the cracks in the theory of evolution.
However, to explain the second stage of the origin of life, evolutionists faced an even greater problem than that of the formation of amino acids-namely, the origin of proteins, the building blocks of life, which are composed of hundreds of different amino acids bonding with each other in a particular order.
Claiming that proteins were formed by chance under natural conditions is even more unrealistic and unreasonable than claiming that amino acids were formed by chance. In the preceding pages we have seen the mathematical impossibility of the haphazard uniting of amino acids in proper sequences to form proteins with probability calculations. Now, we will examine the impossibility of proteins being produced chemically under primordial earth conditions.
The Problem of Protein Synthesis in Water
As we saw before, when combining to form proteins, amino acids form a special bond with one another called the peptide bond. A water molecule is released during the formation of this peptide bond.
This fact definitely refutes the evolutionist explanation that primordial life originated in water, because, according to the “Le Châtelier principle” in chemistry, it is not possible for a reaction that releases water (a condensation reaction) to take place in a hydrous environment. The chances of this kind of a reaction happening in a hydrate environment is said to “have the least probability of occurring” of all chemical reactions.
Hence the ocean, which is claimed to be where life began and amino acids originated, is definitely not an appropriate setting for amino acids to form proteins.262 On the other hand, it would be irrational for evolutionists to change their minds and claim that life originated on land, because the only environment where amino acids could have been protected from ultraviolet radiation is in the oceans and seas. On land, they would be destroyed by ultraviolet rays. The Le Châtelier principle, on the other hand, disproves the claim of the formation of life in the sea. This is another dilemma confronting evolution.
Sydney Fox, who was influenced by Miller’s scenario, formed the above molecules, which he called “proteinoids,” by joining amino acids together. However, these chains of nonfunctioning amino acids had no resemblance to the real proteins that make up the bodies of living things. Actually, all these efforts showed not only that life did not come about by chance, but also that it could not be reproduced in laboratory conditions.
Challenged by the above dilemma, evolutionists began to invent unrealistic scenarios based on this “water problem” that so definitively refuted their theories. Sydney Fox was one of the best known of these researchers. Fox advanced the following theory to solve the problem. According to him, the first amino acids must have been transported to some cliffs near a volcano right after their formation in the primordial ocean. The water contained in this mixture that included the amino acids must have evaporated when the temperature increased above boiling point on the cliffs. The amino acids which were “dried out” in this way, could then have combined to form proteins.
However this “complicated” way out was not accepted by many people in the field, because the amino acids could not have endured such high temperatures. Research confirmed that amino acids are immediately destroyed at very high temperatures.
But Fox did not give up. He combined purified amino acids in the laboratory, “under very special conditions,” by heating them in a dry environment. The amino acids combined, but still no proteins were obtained. What he actually ended up with was simple and disordered loops of amino acids, arbitrarily combined with each other, and these loops were far from resembling any living protein. Furthermore, if Fox had kept the amino acids at a steady temperature, then these useless loops would also have disintegrated.
Another point that nullified the experiment was that Fox did not use the useless end products obtained in Miller’s experiment rather, he used pure amino acids from living organisms. This experiment, however, which was intended to be a continuation of Miller’s experiment, should have started out from the results obtained by Miller. Yet neither Fox, nor any other researcher, used the useless amino acids Miller produced.
Fox’s experiment was not even welcomed in evolutionist circles, because it was clear that the meaningless amino acid chains that he obtained (which he termed “proteinoids”) could not have formed under natural conditions. Moreover, proteins, the basic units of life, still could not be produced. The problem of the origin of proteins remained unsolved. In an article in the popular science magazine, Chemical Engineering News, which appeared in the 1970s, Fox’s experiment was mentioned as follows:
When Watson and Crick discovered the structure of DNA, they revealed that life was much more complicated than had previously been thought.
Sydney Fox and the other researchers managed to unite the amino acids in the shape of “proteinoids” by using very special heating techniques under conditions which in fact did not exist at all in the primordial stages of Earth. Also, they are not at all similar to the very regular proteins present in living things. They are nothing but useless, irregular chemical stains. It was explained that even if such molecules had formed in the early ages, they would definitely be destroyed.263
Indeed, the proteinoids Fox obtained were totally different from real proteins, both in structure and function. The difference between proteins and these proteinoids was as huge as the difference between a piece of high-tech equipment and a heap of unprocessed iron.
Furthermore, there was no chance that even these irregular amino acid chains could have survived in the primordial atmosphere. Harmful and destructive physical and chemical effects caused by heavy exposure to ultraviolet light and other unstable natural conditions would have caused these proteinoids to disintegrate. Because of the Le Châtelier principle, it was also impossible for the amino acids to combine underwater, where ultraviolet rays would not reach them. In view of this, the idea that the proteinoids were the basis of life eventually lost support among scientists.
The Origin of the DNA Molecule
Our examinations so far have shown that the theory of evolution is in a serious quandary at the molecular level. Evolutionists have shed no light on the formation of amino acids at all. The formation of proteins, on the other hand, is another mystery all its own.
Yet the problems are not even limited just to amino acids and proteins: These are only the beginning. Beyond them, the extremely complex structure of the cell leads evolutionists to yet another impasse. The reason for this is that the cell is not just a heap of amino-acid-structured proteins, but rather the most complex system man has ever encountered.
While the theory of evolution was having such trouble providing a coherent explanation for the existence of the molecules that are the basis of the cell structure, developments in the science of genetics and the discovery of nucleic acids (DNA and RNA) produced brand-new problems for the theory. In 1953, James Watson and Francis Crick launched a new age in biology with their work on the structure of DNA.
The molecule known as DNA, which is found in the nucleus of each of the 100 trillion cells in our bodies, contains the complete blueprint for the construction of the human body. The information regarding all the characteristics of a person, from physical appearance to the structure of the inner organs, is recorded in DNA within the sequence of four special bases that make up the giant molecule. These bases are known as A, T, G, and C, according to the initial letters of their names. All the structural differences among people depend on variations in the sequences of these letters. In addition to features such as height, and eye, hair and skin colors, the DNA in a single cell also contains the design of the 206 bones, the 600 muscles, the 100 billion nerve cells (neurons), 1.000 trillion connections between the neurons of the brain, 97,000 kilometers of veins, and the 100 trillion cells of the human body. If we were to write down the information coded in DNA, then we would have to compile a giant library consisting of 900 volumes of 500 pages each. But the information this enormous library would hold is encoded inside the DNA molecules in the cell nucleus, which is far smaller than the 1/100th-of-a-millimeter-long cell itself.
DNA Cannot Be Explained by Non-Design
At this point, there is an important detail that deserves attention. An error in the sequence of the nucleotides making up a gene would render that gene completely useless. When it is considered that there are 200,000 genes in the human body, it becomes clearer how impossible it is for the millions of nucleotides making up these genes to have been formed, in the right sequence, by chance. The evolutionary biologist Frank Salisbury has comments on this impossibility:
A medium protein might include about 300 amino acids. The DNA gene controlling this would have about 1,000 nucleotides in its chain. Since there are four kinds of nucleotides in a DNA chain, one consisting of 1,000 links could exist in 4 1,000 forms. Using a little algebra (logarithms) we can see that 4 1,000 =10 600 . Ten multiplied by itself 600 times gives the figure 1 followed by 600 zeros! This number is completely beyond our comprehension.264
The number 4 1,000 is the equivalent of 10 600 . This means 1 followed by 600 zeros. As 1 with 12 zeros after it indicates a trillion, 600 zeros represents an inconceivable number.
The impossibility of the formation of RNA and DNA by a coincidental accumulation of nucleotides is expressed by the French scientist Paul Auger in this way:
We have to sharply distinguish the two stages in the chance formation of complex molecules such as nucleotides by chemical events. The production of nucleotides one by one-which is possible-and the combination of these within very special sequences. The second is absolutely impossible.265
For many years, Francis Crick believed in the theory of molecular evolution, but eventually even he had to admit to himself that such a complex molecule could not have emerged spontaneously by chance, as the result of an evolutionary process:
An honest man, armed with all the knowledge available to us now, could only state that, in some sense, the origin of life appears at the moment to be almost a miracle.266
The Turkish evolutionist Professor Ali Demirsoy was forced to make the following confession on the issue:
In fact, the probability of the formation of a protein and a nucleic acid (DNA-RNA) is a probability way beyond estimating. Furthermore, the chance of the emergence of a certain protein chain is so slight as to be called astronomic.267
A very interesting paradox emerges at this point: While DNA can only replicate with the help of special proteins (enzymes), the synthesis of these proteins can only be realized by the information encoded in DNA. As they both depend on each other, they have to exist at the same time for replication. Science writer John Horgan explains the dilemma in this way:
DNA cannot do its work, including forming more DNA, without the help of catalyticproteins, or enzymes. In short, proteins cannot form without DNA, but neither can DNA form without proteins.268
This situation once again undermines the scenario that life could have come about by accident. Homer Jacobson, Professor Emeritus of Chemistry, comments:
Directions for the reproduction of plans, for energy and the extraction of parts from the current environment, for the growth sequence, and for the effector mechanism translating instructions into growth-all had to be simultaneously present at that moment [when life began]. This combination of events has seemed an incredibly unlikely happenstance
The quotation above was written two years after the discovery of the structure of DNA by Watson and Crick. But despite all the developments in science, this problem for evolutionists remains unsolved. This is why German biochemist Douglas R. Hofstadter says:
‘How did the Genetic Code, along with the mechanisms for its translation (ribosomes and RNA molecules), originate?’ For the moment, we will have to content ourselves with a sense of wonder and awe, rather than with an answer.270
Stanley Miller and Francis Crick’s close associate from the University of San Diego, California, the highly reputed evolutionist Dr. Leslie Orgel says in an article published in 1994:
It is extremely improbable that proteins and nucleic acids, both of which are structurally complex, arose spontaneously in the same place at the same time. Yet it also seems impossible to have one without the other. And so, at first glance, one might have to conclude that life could never, in fact, have originated by chemical means.271
Alongside all of this, it is chemically impossible for nucleic acids such as DNA and RNA, which possess a definite string of information, to have emerged by chance, or for even one of the nucleotides which compose them to have come about by accident and to have survived and maintained its unadulterated state under the conditions of the primordial world. Even the famous journal Scientific American, which follows an evolutionist line, has been obliged to confess the doubts of evolutionists on this subject:
Even the simpler molecules are produced only in small amounts in realistic experiments simulating possible primitive earth conditions. What is worse, these molecules are generally minor constituents of tars: It remains problematical how they could have been separated and purified through geochemical processes whose normal effects are to make organic mixtures more and more of a jumble. With somewhat more complex molecules these difficulties rapidly increase. In particular a purely geochemical origin of nucleotides (the subunits of DNA and RNA) presents great difficulties.272
Of course, the statement “it is quite impossible for life to have emerged by chemical means” simply means that life is the product of an intelligent design. This “chemical evolution” that evolutionists have been talking about since the beginning of the last century never happened, and is nothing but a myth.
But most evolutionists believe in this and similar totally unscientific fairy tales as if they were true, because accepting intelligent design means accepting creation-and they have conditioned themselves not to accept this truth. One famous biologist from Australia, Michael Denton, discusses the subject in his book Evolution: A Theory in Crisis:
To the skeptic, the proposition that the genetic programmes of higher organisms, consisting of something close to a thousand million bits of information, equivalent to the sequence of letters in a small library of 1,000 volumes, containing in encoded form countless thousands of intricate algorithms controlling, specifying, and ordering the growth and development of billions and billions of cells into the form of a complex organism, were composed by a purely random process is simply an affront to reason. But to the Darwinist, the idea is accepted without a ripple of doubt – the paradigm takes precedence!273
The Invalidity of the RNA World
The discovery in the 1970s that the gases originally existing in the primitive atmosphere of the earth would have rendered amino acid synthesis impossible was a serious blow to the theory of molecular evolution. Evolutionists then had to face the fact that the “primitive atmosphere experiments” by Stanley Miller, Sydney Fox, Cyril Ponnamperuma and others were invalid. For this reason, in the 1980s the evolutionists tried again. As a result, the “RNA World” hypothesis was advanced. This scenario proposed that, not proteins, but rather the RNA molecules that contained the information for proteins, were formed first.
According to this scenario, advanced by Harvard chemist Walter Gilbert in 1986, inspired by the discovery about “ribozymes” by Thomas Cech, billions of years ago an RNA molecule capable of replicating itself formed somehow by accident. Then this RNA molecule started to produce proteins, having been activated by external influences. Thereafter, it became necessary to store this information in a second molecule, and somehow the DNA molecule emerged to do that.
Made up as it is of a chain of impossibilities in each and every stage, this scarcely credible scenario, far from providing any explanation of the origin of life, only magnified the problem, and raised many unanswerable questions:
1. Since it is impossible to accept the coincidental formation of even one of the nucleotides making up RNA, how can it be possible for these imaginary nucleotides to form RNA by coming together in a particular sequence? Evolutionist John Horgan admits the impossibility of the chance formation of RNA
As researchers continue to examine the RNA-World concept closely, more problems emerge. How did RNA initially arise? RNA and its components are difficult to synthesize in a laboratory under the best of conditions, much less under really plausible ones.274
2. Even if we suppose that it formed by chance, how could this RNA, consisting of just a nucleotide chain, have “decided” to self-replicate, and with what kind of mechanism could it have carried out this self-replicating process? Where did it find the nucleotides it used while self-replicating? Even evolutionist microbiologists Gerald Joyce and Leslie Orgel express the desperate nature of the situtation in their book In the RNA World:
This discussion has, in a sense, focused on a straw man: the myth of a self-replicating RNA molecule that arose de novo from a soup of random polynucleotides. Not only is such a notion unrealistic in light of our current understanding of prebiotic chemistry, but it would strain the credulity of even an optimist’s view of RNA’s catalytic potential.275
3. Even if we suppose that there was self-replicating RNA in the primordial world, that numerous amino acids of every type ready to be used by RNA were available, and that all of these impossibilities somehow took place, the situation still does not lead to the formation of even one single protein. For RNA only includes information concerning the structure of proteins. Amino acids, on the other hand, are raw materials. Nevertheless, there is no mechanism for the production of proteins. To consider the existence of RNA sufficient for protein production is as nonsensical as expecting a car to assemble itself by simply throwing the blueprint onto a heap of parts piled up on top of each other. A blueprint cannot produce a car all by itself without a factory and workers to assemble the parts according to the instructions contained in the blueprint in the same way, the blueprint contained in RNA cannot produce proteins by itself without the cooperation of other cellular components which follow the instructions contained in the RNA.
Proteins are produced in the ribosome factory with the help of many enzymes, and as a result of extremely complex processes within the cell. The ribosome is a complex cell organelle made up of proteins. This leads, therefore, to another unreasonable supposition-that ribosomes, too, should have come into existence by chance at the same time. Even Nobel Prize winner Jacques Monod, who was one of the most fanatical defenders of evolution-and atheism-explained that protein synthesis can by no means be considered to depend merely on the information in the nucleic acids:
The code is meaningless unless translated. The modern cell’s translating machinery consists of at least 50 macromolecular components, which are themselves coded in DNA: the code cannot be translated otherwise than by products of translation themselves. It is the modern expression of omne vivum ex ovo. When and how did this circle become closed? It is exceedingly difficult to imagine.276
How could an RNA chain in the primordial world have taken such a decision, and what methods could it have employed to make protein production happen by doing the work of 50 specialized particles on its own? Evolutionists have no answer to these questions. One article in the preeminent scientific journal Nature makes it clear that the concept of “self-replicating RNA” is a complete product of fantasy, and that actually this kind of RNA has not been produced in any experiment:
DNA replication is so error-prone that it needs the prior existence of protein enzymes to improve the copying fidelity of a gene-size piece of DNA. “Catch-22” say Maynard Smith and Szathmary. So, wheel on RNA with its now recognized properties of carrying both informational and enzymatic activity, leading the authors to state: “In essence, the first RNA molecules did not need a protein polymerase to replicate them they replicated themselves.” Is this a fact or a hope? I would have thought it relevant to point out for ‘biologists in general’ that not one self-replicating RNA has emerged to date from quadrillions (10 24 ) of artificially synthesized, random RNA sequences.277
Dr. Leslie Orgel, one of the associates of Stanley Miller and Francis Crick from the University of California at San Diego, uses the term “scenario” for the possibility of “the origination of life through the RNA World.” Orgel described what kind of features this RNA would have had to have and how impossible these would have been in his article “The Origin of Life,” published in Scientific American in October 1994:
This scenario could have occurred, we noted, if prebiotic RNA had two properties not evident today: A capacity to replicate without the help of proteins and an ability to catalyze every step of protein synthesis.278
As should by now be clear, to expect these two complex and extremely essential processes from a molecule such as RNA is againt scientific thought. Concrete scientific facts, on the other hand, makes it explicit that the RNA World hypothesis, which is a new model proposed for the chance formation of life, is an equally implausible fable.
John Horgan, in his book The End of Science, reports that Stanley Miller viewed the theories subsequently put forward regarding the origin of life as quite meaningless (It will be recalled that Miller was the originator of the famous Miller Experiment, which was later revealed to be invalid.):
In fact, almost 40 years after his original experiment, Miller told me that solving the riddle of the origin of life had turned out to be more difficult than he or anyone else had envisioned Miller seemed unimpressed with any of the current proposals on the origin of life, referring to them as “nonsense” or “paper chemistry.” He was so contemptuous of some hypotheses that, when I asked his opinion of them, he merely shook his head, sighed deeply, and snickered-as if overcome by the folly of humanity. Stuart Kauffman’s theory of autocatalysis fell into this category. “Running equations through a computer does not constitute an experiment,” Miller sniffed. Miller acknowledged that scientists may never know precisely where and when life emerged.279
This statement, by a pioneer of the struggle to find an evolutionary explanation for the origin of life, clearly reflects the despair felt by evolutionist scientists over the cul-de-sac they find themselves in.
Can Design Be Explained by Coincidence?
So far, we have examined how impossible the accidental formation of life is. Let us again ignore these impossibilities for just a moment. Let us suppose that millions of years ago a cell was formed which had acquired everything necessary for life, and that it duly “came to life.” Evolution again collapses at this point. For even if this cell had existed for a while, it would eventually have died and after its death, nothing would have remained, and everything would have reverted to where it had started. This is because this first living cell, lacking any genetic information, would not have been able to reproduce and start a new generation. Life would have ended with its death.
This illustration shows the sketch of the chemical reactions taking place in a single cell. These intricate activities in the cell, which can only be viewed with an electron microscope, continue to take place flawlessly and ceaselessly.
The genetic system does not only consist of DNA. The following things must also exist in the same environment: enzymes to read the code on the DNA, messenger RNA to be produced after reading these codes, a ribosome to which messenger RNA will attach according to this code, transfer RNA to transfer the amino acids to the ribosome for use in production, and extremely complex enzymes to carry out numerous intermediary processes. Such an environment cannot exist anywhere apart from a totally isolated and completely controlled environment such as the cell, where all the essential raw materials and energy resources exist.
As a result, organic matter can self-reproduce only if it exists as a fully developed cell, with all its organelles. This means that the first cell on earth was formed “all of a sudden,” together with its incredibly complex structure.
So, if a complex structure came into existence all of a sudden, what does this mean?
Let us ask this question with an example. Let us liken the cell to a high-tech car in terms of its complexity. (In fact, the cell is a much more complex and developed system than a car .) Now let us ask the following question: What would you think if you went out hiking in the depths of a thick forest and ran across a brand-new car among the trees? Would you imagine that various elements in the forest had come together by chance over millions of years and produced such a vehicle? All the parts in the car are made of products such as iron, copper, and rubber-the raw ingredients for which are all found on the earth-but would this fact lead you to think that these materials had synthesized “by chance” and then come together and manufactured such a car?
There is no doubt that anyone with a sound mind would realize that the car was the product of an intelligent design-in other words, a factory-and wonder what it was doing there in the middle of the forest. The sudden emergence of a complex structure in a complete form, quite out of the blue, shows that this is the work of an intelligent design.
Believing that pure chance can produce perfect designs goes well beyond the bounds of reason. Yet every “explanation” put forward by the theory of evolution regarding the origin of life is like that. One outspoken authority on this issue is the famous French zoologist Pierre-Paul Grassé, the former president of the French Academy of Sciences. Grassé is an evolutionist, yet he acknowledges that Darwinist theory is unable to explain life and makes a point about the logic of “coincidence,” which is the backbone of Darwinism:
The opportune appearance of mutations permitting animals and plants to meet their needs seems hard to believe. Yet the Darwinian theory is even more demanding: A single plant, a single animal would require thousands and thousands of lucky, appropriate events. Thus, miracles would become the rule: events with an infinitesimal probability could not fail to occur There is no law against daydreaming, but science must not indulge in it.280
All living things in the world, all of which are clear examples of the intelligent planning we have just been discussing, are at the same time living evidence that coincidence can have no role to play in their existence. Each of its component parts-never mind a whole living creature-contains structures and systems so complex that they cannot be the work of coincidence. We need go no further than our own bodies to find examples of this.
One example of this is our eyes. The human eye sees by the working together of some 40 separate parts. If one of these is not present, the eye will be useless. Each of these 40 parts possesses complicated designs within itself. The retina at the back of the eye, for instance, is made up of 11 layers. Each layer has a different function. The chemical processes that go on inside the retina are so complex that they can only be explained with pages full of formulae and diagrams.
The theory of evolution is unable to account for the emergence of even such a flawless and complex structure as a single eye by means of “accident,” let alone life itself, or mankind.
So, what does this extraordinary design in living things prove to us about the origin of life? As we made clear in the opening part of this book, only two different accounts can be given regarding the origin of life. One is evolution, the other intelligent creation. Since the evolution claim is impossible, scientific discoveries therefore prove the truth of creation. This truth may surprise some scientists, who from the nineteenth century to the present have seen the concept of “creation” as unscientific, but science can only progress by overcoming shocks of this kind and accepting the truth. Chandra Wickramasinghe describes the reality he faced as a scientist who had been told throughout his life that life had emerged as a result of chance coincidences:
Process of Spermatogenesis: 2 Main Stages
The male germinal cells which produce the sperms are known as the primary germinal cells or primordial cells.
The primordial cells pass through following three phases for the formation of spermatids:
(i) The Multiplication Phase:
The undifferentiated germ cells or primordial cells contain large-sized and chromatin rich nuclei. These cells multiply by repeated mitotic divisions and produce the cells which are known as the spermatogonia (Gr., sperma = sperm or seed gone = offspring). Each spermatogonium is diploid and contains 2X number or chromosomes.
In the growth phase, the spermatogonial cells accumulate large amount of nutrition and chromatin material. Now each spermatogonial cell is known as the primary spermatocyte.
(iii) The Maturation Phase:
The primary spermatocytes are ready for first meiotic or maturation division. The homologous chromosomes start pairing (synapsis), each homologous chromosome splits longitudinally and by the chiasma formation the exchange of genetic material or crossing over takes place between the chromatids of the homologous chromosomes. The DNA amount is duplicated in the beginning of the division.
By first meiotic division or homotypic division, two secondary spermatocytes are formed. Each secondary spermatocyte is haploid and contains X number of chromosomes. Each secondary spermatocyte passes through the second maturation or second meiotic or heterotypic division and produces two spermatids.
Thus, by a meiotic or maturation division, a diploid spermatogonium produces four haploid spermatids. These spermatids cannot act directly as the gametes so they have to pass through the next phase, the spermiogenesis.
Spermatogenesis: Stage # 2. Spermiogenesis:
The metamorphosis or differentiation of the spermatids into the sperms is known as spermiogenesis. Because the sperm or spermatozoon is a very active and mobile cell so as to provide great amount of mobility to the sperm, the superfluous material of the developing spermsis discarded.
For the reduction of the weight of the sperms, following changes occur in the spermatids:
(i) Changes in the Nucleus:
The nucleus loses water from the nuclear sap, shrinks and assumes different shapes in the different animals. The sperm nucleus in man and bull becomes ovoid and laterally flattened. In rodents and amphibians, the sperm nucleus becomes scimitar- shaped with pointed tip. In birds and molluscs, the nucleus becomes spirally twisted like a cork screw.
The bivalve molluscs have the round sperm nucleus. The shape of the nucleus also determines the shape of the sperm head which becomes fully adapted for the active propulsion through the water. The RNA contents of the nucleus and the nucleolus are greatly reduced, The DNA becomes more concentrated and the chromatin material becomes closely packed into small volume.
(ii) Acrosome Formation:
The acrosome occurs at the anterior side of the sperm nucleus and contains proteases enzymes which help it in the easy penetration inside the egg. The acrosome is formed by the Golgi apparatus. The Golgi apparatus is concentrated near the anterior end of the sperm nucleus to form the acrosome.
One or two vacuoles of the apparatus become large and occupy the place between the tubes of Golgi apparatus. Soon after a dense granule known as the proacrosomal granule develops inside the vacuole. Leblond (1955) found the proacrosomal granule rich in the mucopolysaccharides. The proacrosomal granule attaches with the anterior end of the nucleus and enlarges into the acrosome.
The membranes of Golgi vacuoles form the double membrane (unit membrane of lipoprotein) sheath around the acrosome and forms the cap-like structure of the spermatozoon. The rest of the Golgi apparatus becomes reduced and discarded from the sperm as Golgi rest. In the sperms of certain animals, an acrosomal cone or axial body also develops in between the acrosome and the nucleus.
The two centrioles of the spermatids become arranged one after the other behind the nucleus. The anterior one is known as the proximal centriole and posterior one is known as the distal centriole. The distal centriole changes into the basal bodies and gives rise to the axial filament of the sperm.
The axial filament or the flagellum is composed of a pair of central longitudinal fibres and nine peripheral fibres. The distal centriole and the basal part of the axial filament occur in the middle piece of the spermatozoa. The mitochondria of the spermatids fuse together and twist spirally around the axial filament.
Thus, most of the cytoplasmic portion of the spermatid except the nucleus, acrosome, centriole, mitochondria and axial filament, is discarded during the spermiogenesis.
How is the scientific method used by biologists?
Quick recap: Biologists and other scientists use the scientific method to ask questions about the natural world. The scientific method begins with an observation, which leads the scientist to ask a question. She or he then comes up with a hypothesis, a testable explanation that addresses the question.
A hypothesis isn’t necessarily right. Instead, it’s a “best guess,” and the scientist must test it to see if it’s actually correct. Scientists test hypotheses by making predictions: if hypothesis X is right, then Y should be true. Then, they do experiments or make observations to see if the predictions are correct. If they are, the hypothesis is supported. If they aren’t, it may be time for a new hypothesis.
Hypotheses are tested using controlled experiments
What are the key ingredients of a controlled experiment? To illustrate, let’s consider a simple (even silly) example.
Suppose I decide to grow bean sprouts in my kitchen, near the window. I put bean seeds in a pot with soil, set them on the windowsill, and wait for them to sprout. However, after several weeks, I have no sprouts. Why not? Well…it turns out I forgot to water the seeds. So, I hypothesize that they didn’t sprout due to lack of water.
To test my hypothesis, I do a controlled experiment. In this experiment, I set up two identical pots. Both contain ten bean seeds planted in the same type of soil, and both are placed in the same window. In fact, there is only one thing that I do differently to the two pots:
- One pot of seeds gets watered every afternoon.
- The other pot of seeds doesn’t get any water at all.
After a week, nine out of ten seeds in the watered pot have sprouted, while none of the seeds in the dry pot have sprouted. It looks like the “seeds need water” hypothesis is probably correct!
Let’s see how this simple example illustrates the parts of a controlled experiment.
Control and experimental groups
There are two groups in the experiment, and they are identical except that one receives a treatment (water) while the other does not. The group that receives the treatment in an experiment (here, the watered pot) is called the experimental group, while the group that does not receive the treatment (here, the dry pot) is called the control group. The control group provides a baseline that lets us see if the treatment has an effect. Controls can be positive controls to demonstrate that the process or treatment actually works, or they can be negative controls, where no change should occur during the experiment.
Independent and dependent variables
The factor that is different between the control and experimental groups (in this case, the amount of water) is known as the independent variable. This variable is independent because it does not depend on what happens in the experiment. Instead, it is something that the experimenter applies or chooses him/herself. Experiments can have more than one independent variable.
In contrast, the dependent variable in an experiment is the response that’s measured to see if the treatment had an effect. In this case, the fraction of bean seeds that sprouted is the dependent variable. The dependent variable (fraction of seeds sprouting) depends on the independent variable (the amount of water), and not vice versa.
Experimental data (singular: datum) are observations made during the experiment. In this case, the data we collected were the number of bean sprouts in each pot after a week.
Properties of Life
All living organisms share several key characteristics or functions: order, sensitivity or response to the environment, reproduction, growth and development, regulation, homeostasis, and energy processing. When viewed together, these characteristics serve to define life.
Figure 1. A toad represents a highly organized structure consisting of cells, tissues, organs, and organ systems.
Organisms are highly organized, coordinated structures that consist of one or more cells. Even very simple, single-celled organisms are remarkably complex: inside each cell, atoms make up molecules these in turn make up cell organelles and other cellular inclusions.
In multicellular organisms (Figure 1), similar cells form tissues. Tissues, in turn, collaborate to create organs (body structures with a distinct function). Organs work together to form organ systems.
Sensitivity or Response to Stimuli
Organisms respond to diverse stimuli. For example, plants can bend toward a source of light, climb on fences and walls, or respond to touch (Figure 2).
Figure 2.The leaves of this sensitive plant (Mimosa pudica) will instantly droop and fold when touched. After a few minutes, the plant returns to normal. (credit: Alex Lomas)
Even tiny bacteria can move toward or away from chemicals (a process called chemotaxis) or light (phototaxis). Movement toward a stimulus is considered a positive response, while movement away from a stimulus is considered a negative response.
Watch this video to see how plants respond to a stimulus—from opening to light, to wrapping a tendril around a branch, to capturing prey.
Single-celled organisms reproduce by first duplicating their DNA, and then dividing it equally as the cell prepares to divide to form two new cells. Multicellular organisms often produce specialized reproductive germline cells that will form new individuals. When reproduction occurs, genes containing DNA are passed along to an organism’s offspring. These genes ensure that the offspring will belong to the same species and will have similar characteristics, such as size and shape.
Growth and Development
Figure 3. Although no two look alike, these puppies have inherited genes from both parents and share many of the same characteristics.
Organisms grow and develop following specific instructions coded for by their genes. These genes provide instructions that will direct cellular growth and development, ensuring that a species’ young (Figure 3) will grow up to exhibit many of the same characteristics as its parents.
Even the smallest organisms are complex and require multiple regulatory mechanisms to coordinate internal functions, respond to stimuli, and cope with environmental stresses. Two examples of internal functions regulated in an organism are nutrient transport and blood flow. Organs (groups of tissues working together) perform specific functions, such as carrying oxygen throughout the body, removing wastes, delivering nutrients to every cell, and cooling the body.
Figure 4. Polar bears (Ursus maritimus) and other mammals living in ice-covered regions maintain their body temperature by generating heat and reducing heat loss through thick fur and a dense layer of fat under their skin. (credit: “longhorndave”/Flickr)
In order to function properly, cells need to have appropriate conditions such as proper temperature, pH, and appropriate concentration of diverse chemicals. These conditions may, however, change from one moment to the next. Organisms are able to maintain internal conditions within a narrow range almost constantly, despite environmental changes, through homeostasis (literally, “steady state”)—the ability of an organism to maintain constant internal conditions. For example, an organism needs to regulate body temperature through a process known as thermoregulation. Organisms that live in cold climates, such as the polar bear (Figure 4), have body structures that help them withstand low temperatures and conserve body heat. Structures that aid in this type of insulation include fur, feathers, blubber, and fat. In hot climates, organisms have methods (such as perspiration in humans or panting in dogs) that help them to shed excess body heat.
All organisms use a source of energy for their metabolic activities. Some organisms capture energy from the sun and convert it into chemical energy in food (photosynthesis) others use chemical energy in molecules they take in as food (cellular respiration).
Figure 5. The California condor (Gymnogyps californianus) uses chemical energy derived from food to power flight. California condors are an endangered species this bird has a wing tag that helps biologists identify the individual.
How Did Life on Earth Emerged? Understand the Hypotheses
The most recurrent explanation for the phenomenon of life on earth is mythological. People from various parts of the world developed myths to explain the origin of animals and human beings. Some of those myths were incorporated into religions and almost all religions have metaphorical or transcendental explanations for the origin of life on the planet.
With the development of science, new attempts to explain this have emerged. Notable among them are the spontaneous generation hypothesis, or abiogenesis, which assertes that living organisms were created from non-living materials the cosmic panspermia hypothesis, which is the theory that life on earth is a result of seeding from the outer space the autotrophic hypothesis, according to which the first living organisms were autotrophs and the heterotrophic hypothesis, which is the most accepted nowadays, and which affirms that life emerged from heterotrophic cells.
At the end of the 1980s, a new hypothesis known as the RNA world hypothesis was presented. This hypothesis asserts that primitive life had only RNA as genetic material and structural molecules, and that it later turned into DNA and proteins. The RNA world hypothesis is strengthened by the fact that RNA can play the role of a catalyst, like enzymes, and by discoveries that some bacteria have ribosomes made of only RNA without proteins attached to it.
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5. What is the spontaneous generation hypothesis?
The spontaneous generation hypothesis, or abiogenesis, claims that life on earth came from non-living materials. For example, the fact that, over time, rats appeared around waste was considered to be a confirmation of this hypothesis in the past. Some supporters of spontaneous generation associated it with the existence of an active principle (the vital elan) that they claimed to be the source of life, a theory known as vitalism.
6. How did the experiments of Redi and Pasteur refute the spontaneous generation hypothesis?
To refute the spontaneous generation hypothesis, many experiments were performed. Francisco Redi, in 1668, verified that maggots appeared on meat only when it was exposed to the environment within closed environments, they did not appear. In 1862, Louis Pasteur working, with swan-neck flasks, definitively refuted the abiogenesis hypothesis. In this experiment, Pasteur demonstrated that boiled (to kill microorganisms) nutritive soups put in swan-neck flasks (with a curved down mouth so that microorganisms could not enter easily) were not contaminated with microorganisms whereas the same soups within flasks with mouth open upwards were contaminated in a few days. The fact that both flasks were open refuted the vitalist argument that the vital elan could not enter the flasks. Pasteur broke the swan-necks of the flasks to demonstrate that the proliferation of microorganisms could happen if those organisms were able to reach the broth.
7. What is panspermia?
Panspermia is a hypothesis that describes life on earth as not originating on the planet. The idea is that the first living organisms that colonized the earth came from outer space, from other planets or even from other galaxies by traveling on meteorites, comets, etc. According to this hypothesis, even the type of life that now exists on earth could have also been seeded intentionally by extraterrestrial beings in other stellar and planetary systems.
The Autotrophic Hypothesis
8. What is the autotrophic hypothesis of the origin of life?
The autotrophic hypothesis of the origin of life claims that the first living organisms on earth were producers of their own food, just like plants and chemosynthetic microorganisms.
The Heterotrophic Hypothesis
9. What is the heterotrophic hypothesis of the origin of life?
According to the heterotrophic hypothesis, the first living organisms were very simple heterotrophic organisms, that is, organisms that are not producers of their own food, which emerged from the gradual incorporation of organic molecules into small organized structures (the coacervates). According to it, the first organic molecules in turn appeared from substances from the earth's primitive atmosphere subject to strong electrical discharges, solar radiation and high temperatures.
10. What is the most accepted hypothesis on the origin of life on earth? How does it compare to the other main hypotheses?
The heterotrophic hypothesis is the strongest and most accepted hypothesis on the origin of life.
The spontaneous generation hypothesis has been excluded by the experiments of Pasteur. The panspermia hypothesis has not yet been completely refuted, but it is not well-accepted since it would be necessary to explain how living organisms could survive long space journeys under conditions of extreme temperatures as well as to clarify the manner in which they could resist the high temperatures faced when entering the earth's atmosphere. The autotrophic hypothesis is weakened if you take into account the fact that the production of organic material from inorganic substances is a highly complex process requiring diversified enzymatic systems and that the existence of complex metabolic reactions on the primitive earth was not probable.
Earth's Primitive Atmosphere
11. Before the emergence of life, what gases composed the earth's primitive atmosphere?
The earth's primitive atmosphere was basically formed of methane, hydrogen, ammonia and water vapor.
12. What are the main components of the earth's atmosphere in our time?
The present atmosphere is composed mainly of molecular nitrogen (N₂) and molecular oxygen (O₂). Nitrogen is the most abundant gas, accounting for approximately 80% of the total volume. Oxygen makes up about 20%. Other gases exist in the atmosphere at a low percentage. (Of great concern is the increase in the amount of carbon dioxide due to human activity, the cause of the global warming threat.)
13. Did the earth's primitive atmosphere contain molecular oxygen? How has that molecule become abundant?
The presence of molecular oxygen in the primitive atmosphere was probably minimal and extremely rare. Oxygen became abundant with the emergence of photosynthetic organisms, approximately 1.5 billion years after the appearance of life on the planet.
The Stanley Miller Experiment
14. Which physical elements contributed to the large amount of energy available on primitive earth at the time of the origin of life?
3.5 billion years ago, the water cycle was faster than it is today, resulting in harsh storms with intense electrical discharge. There was also no chemical protection from the ozone layer against ultraviolet radiation. The temperatures in the atmosphere and on the planet's surface were very high. Electricity, radiation and heat constituted large available energy sources.
15. What was Stanley Miller's experiment (1953) on the origin of life?
In 1953, Stanley Miller arranged an experimental apparatus that simulated the atmospheric conditions of primitive earth. The experiment contained a mixture of methane, ammonia, hydrogen and circulating water that, when heated, was transformed into vapor. He submitted the mixture to a continuous bombardment of electrical discharge and, after days, obtained a liquid residuel within which he discovered organic molecules, and among them surprisingly the amino acids glycine and alanine, the most abundant components of proteins. Other researchers reproduced the Miller experiment and also noted the formation of other organic molecules such as lipids, carbohydrates and nucleotides.
16. What are coacervates?
Coacervatesਊre small structures made of the accumulation of organic molecules under a water solution. By electrical attraction, the molecules join to form bigger and more organized particles distinct from the fluid environment, producing a membrane-like structure that separates the internal region of the coacervate from the exterior. Coacervates could divide themselves and also absorb and excrete substances. It is believed that these structures may have been the precursors to cells.
17. How can coacervates be formed of phospholipids or polypeptides?
Phospholipids are amphipathic molecules, meaning that they present a polar portion and a nonpolar portion. When they come into contact with water, these molecules tend to spontaneously unite and organize themselves to form membranes that create a closed interior space separate from the exterior environment. Polypeptide chains in turn can attract water (by electrical attraction) to form a surrounding water layer and also to create an organized structure with a delimited interior space.
18. How could coacervates have facilitated the emergence of life on earth?
Coacervates probably provided a nitid separation between the internal and external environment and, as a result, the organic material within them was not lost in the ocean. The enzymatic action inside that internal environment could develop in different manners, increasing the speed of specific chemical reactions. Coacervates also allowed a selective flow of molecules across their membrane. Since they contained different molecules and were differently organized from each other, coacervates could have promoted a competition for molecules from the environment, creating an evolutionary selection process.
The Endosymbiotic Hypothesis
19. What is the evolutionary origin of the internal membranous organelles of the cell?
It is accepted that the internal membranous organelles of eukaryotic cells, such as the Golgi apparatus and the endoplasmic reticulum, appeared from the invaginations of the external membrane of primitive cells.
20. How have prokaryotic cells produced aerobic eukaryotic cells and photosynthetic aerobic eukaryotic cells?
According to the most accepted hypothesis, aerobic eukaryotic cells emerged from the relationship between aerobic prokaryotes engulfed by primitive anaerobic eukaryotic cells. It claims that this is the origin of mitochondria, which were aerobic bacteria engulfed by eukaryotic anaerobes during their primitive stages. This hypothesis is called the endosymbiotic hypothesis on the origin of mitochondria.
The theory also claims that chloroplasts would appeared through endosymbiosis due to the entry of photosynthetic prokaryotes into aerobic eukaryotes, establishing a mutualist ecological interaction.
21. What evidence strengthens the hypothesis that chloroplasts were photosynthetic prokaryotes and mitochondria were aerobic prokaryotes?
The fact that chloroplasts are the organelles responsible for photosynthesis in plants leads to the supposition that before symbiosis, they were autotrophic prokaryotes. Mitochondria are assumed to have once been aerobic prokaryotes because they are the center of aerobic cellular respiration, the powerhouse of eukaryotic cells.
The endosymbiotic hypothesis to explain the emergence of aerobic and autotrophic eukaryotic organisms is further strengthened by the following evidence: chloroplasts as well as mitochondria have their own DNA, which is similar to bacterial DNA chloroplasts and mitochondria reproduce asexually by binary division, like bacteria do both have ribosomes and synthesize proteins.
The Origin of Photosynthesis and Aerobic Life
22. How did the first fermenting autotrophs appear? What about the first aerobic organisms?
The heterotrophic hypothesis claims that the first living organisms were fermenting heterotrophs. Fermentation released carbon dioxide (CO₂) and the atmosphere then became rich in this gas. Through mutation and natural selection, organisms capable of using carbon dioxide and light to synthesize organic material appeared. These would have been the first photosynthetic organisms (and which were also fermenting organisms, since there was no abundance of oxygen).
Since photosynthesis is a reaction that releases molecular oxygen, with the emergence of fermenting autotrophs, this gas became available. Some organisms then developed aerobic respiration using O₂, a highly efficient method to produce energy.
23. Why is it more probable that photosynthetic prokaryotes appeared before aerobic eukaryotes?
It is more probable that photosynthetic prokaryotes appeared before aerobic eukaryotes because, without photosynthesis, the earth's atmosphere would not be rich in molecular oxygen and, without oxygen, the existence of aerobic organisms would not be possible.
24. What is an argument that shows that the emergence of photosynthetic organisms was crucial in life reaching the surface of the sea and later dry land?
Ultraviolet radiation from the sun was not prevented from reaching the surface of primitive earth. Therefore, the development of life on dry land or even near the surface of the sea was impossible (it is probable that the first living organisms lived submerged in deep water to avoid destruction by solar radiation). This was only possible after the appearance of photosynthetic organisms and the subsequent filling of the atmosphere with oxygen released by them to form the atmospheric ozone layer that filters ultraviolet radiation.
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Charles E. Hess Department of Environmental Horticulture University of California Davis, CA 95616 Research in the biology of adventitious root formation has a special place in science.
Charles E. Hess Department of Environmental Horticulture University of California Davis, CA 95616 Research in the biology of adventitious root formation has a special place in science. It provides an excellent forum in which to pursue fundamental research on the regulation of plant growth and development. At the same time the results of the research have been quickly applied by commercial plant propagators, agronomists, foresters and horticulturists (see the chapter by Kovar and Kuchenbuch, by Ritchie, and by Davies and coworkers in this volume). In an era when there is great interest in speeding technology transfer, the experiences gained in research in adventitious root formation may provide useful examples for other areas of science. Interaction between the fundamental and the applied have been and continue to be facilitated by the establishment, in 1951, of the Plant Propagators' Society, which has evolved into the International Plant Propagators' Society, with active programs in six regions around the world. It is a unique organization which brings together researchers in universities, botanical gardens and arboreta, and commercial plant propagators. In this synergistic environment new knowledge is rapidly transferred and new ideas for fundamental research evolve from the presentations and discussions by experienced plant propagators. In the past 50 years, based on research related to the biology of adventitious root formation, advances in plant propagation have been made on two major fronts.