Abiogenesis Is a Likely Explanation for Life on Earth
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Abiogenesis is a likely explanation for life on Earth.
Abiogenesis: "The supposed development of living organisms from nonliving matter."
Likely: "Possessing or displaying the qualities or characteristics that makes something probable."
Explanation: "Something that explains."
Life: "The property or quality that distinguishes living organisms from dead organisms and inanimate matter, manifested in functions such as metabolism, growth, reproduction, and response to stimuli or adaptation to the environment originating from within the organism."
Earth: "The third planet from the sun..."
1. The first round is for acceptance.
2. A forfeit or concession is not allowed.
3. No semantics or trolling.
4. All arguments and sources must be visible inside this debate.
5. Debate resolution, definitions, rules, and structure cannot be changed without asking in the comments before you post your round 1 argument.Debate resolution, definitions, rules, and structure cannot be changed in the middle of the debate.Voters, in the case of the breaking of any of these rules by either debater, all seven points in voting should be given to the other person.
Round 1: Acceptance
Round 2: Presenting all arguments (no rebuttals by con)
Round 3: Refutation of opponent's arguments (no new arguments)
Round 4: Defending your original arguments and conclusion (no new arguments)
I would like to thank creationtruth for accepting this debate.
Composition of the Early Atmosphere
The early Earth's atmosphere was different than today's. For one thing, there was much less free oxygen. The composition of the atmosphere is very important in determining how life could have been created naturally. "Taking a clue from Earth's sibling planets, we might expect high concentrations of carbon dioxide (CO2),with small amounts of methane (CH4), and ammonia (NH3). Hydrogen and nitrogen probably also were present, as H2 and N2, as was hydrogen sulfide (H2S). Hydrogen has a tendency to leave the planet. Thus, it would have quickly reached low levels."
The Origin of Life From Simple Organic Compounds
The first step was the creation of amino acids, the building blocks of proteins, from the contents of Earth's atmosphere. The Miller-Urey experiment showed how this could occur. "Essential to the spontaneous origin of life was the availability of organic molecules as building blocks. The famous prebiotic soup’ experiment by Stanley Miller had shown that amino acids, the building blocks of proteins, arose among other small organic molecules spontaneously by reacting a mixture of methane, hydrogen, ammonia and water in a spark discharge apparatus. These conditions were assumed to simulate those on the primitive Earth. Already in 1922 Oparin had proposed that the early Earth had such a reducing atmosphere... It was suggested that only in a reducing atmosphere like this, synthesis of organic molecules – also sugars and organic bases, building blocks of nucleotides – would have been possible in large amounts."(Note that when the author uses the term "spontaneously", he refers to the reaction of molecules into compouds; it's not like the compounds suddenly came into existence.)
An illustration of the Miller-Urey experiment can be seen here:
The second step was the creation of RNA. Again, this could have been achieved in the conditions of the early Earth. On the early Earth, RNA was dominant for storing genetic information. "Here we show that activated pyrimidine ribonucleotides can be formed in a short sequence that bypasses free ribose and the nucleobases, and instead proceeds through arabinose amino-oxazoline and anhydronucleoside intermediates. The starting materials for the synthesis - cyanamide, cyanoacetylene, glycolaldehyde, glyceraldehyde and inorganic phosphate—are plausible prebiotic feedstock molecules, and the conditions of the synthesis are consistent with potential early-Earth geochemical models.""
This chart below shows how this process could occur:
Caption: "Pyrimidine ribonucleotide assembly options. Previously assumed synthesis of b-ribocytidine-2’,3’-cyclic phosphate 1 (blue; note the failure of the step in which cytosine 3 and ribose 4 are proposed to condense together) and the successful new synthesis described here (green). p, pyranose; f, furanose. (5 = Cyanoacetaldehyde, 6 = urea 6, cyanoacetylene 7, 8= cyanamide, 9 = glyceraldehyde, 10 = glycolaldehyde, 11 = 2-amino-oxazole, 12= pentose amino-oxazoline, arabinose derivative, 13 = anhydroarabinonucleoside)."
The creation of long strands of these ribonucleotides, important for the large chains needed to store genetic information, could have been catalyzed in a number of ways, one of which is a particular type of clay present on the early Earth. "Research from James Ferris' group at Rensselaer Polytechnic Institute suggests that the formation of long strands of RNA may have been catalyzed by clays such as montmorillonite. The charged clay surface attracts the nucleotides and the increased local concentration of nucleotides causes bond formation between nucleotides, forming a polymer of RNA."
Another important component of RNA is the ability to replicate. Otherwise, new organisms could not be created. Ribozymes are RNA molecules that catalyze certain biochemical reactions, including RNA replication (this specific type of ribozyme is called a replicase). These replicases, being RNA molecules themselves, could easily have been found in addition to other types of RNA molecules. "Recently, however, the Hollinger group (MRC, UK) discovered an ice-water stabilized RNA polymerase ribozyme that is capable of copying strands of RNA that were over 200 basepairs long - longer than the ribozyme itself - suggesting that a self-replicating RNA is indeed possible."
The origin of DNA is a bit murkier. While theoretically possible, it is much more likely that DNA evolved from RNA than DNA evolving all by itself. How this could happen is very complex, but the research has been done. "We are reasonably sure now that DNA and DNA replication mechanisms appeared late in early life history, and that DNA originated from RNA in an RNA/protein world. The origin and evolution of DNA replication mechanisms thus occurred at a critical period of life evolution that encompasses the late RNA world and the emergence of the Last Universal Cellular Ancestor (LUCA) to the present three domains of life (Eukarya, Bacteria and Archaea.)."
The third and final step came from the creation of fatty acids. These fatty acids would envelope an RNA strand. Fatty acids are a type of semi-permeable membrane, allowing the RNA strand access to the environment without it escaping or encountering harmful substances. In addition, without fatty acids, replicases would make copies of every RNA molecule around it, inhibiting the spread of RNA. Still further, fatty acids helped the early RNA molecules to store energy. "Some scientists have proposed that hydrothermal vents may have been sites where prebiotically important molecules, including fatty acids, were formed... Research has shown that some minerals can catalyze the stepwise formation of hydrocarbon tails of fatty acids from hydrogen and carbon monoxide gases -- gases that may have been released from hydrothermal vents. Fatty acids of various lengths are eventually released into the surrounding water.
Now that we have amino acids, RNA (and later DNA), and fatty acids, we can get to so-called "protolife" in the form of the protocell from the collection of these elements. The next process would be to start to coalesce these life materials into a living organism. "The group of Jack Szostak has performed extensive and plausible studies that these fatty acid vesicles as containers for RNA would have allowed growth and replication merely by physico-chemical mechanisms, until a more sophisticated membrane machinery, steered by the cell itself and more resembling what is found in current organisms, would have taken their place... The group of Szostak also has demonstrated that nucleotides can pass through prebiotically plausible fatty-acid based vesicles and that non-enzymatic template copying of a model oligo dC DNA template can take place within them, which, in connection with the studies of vesicle growth and division, reveals in principle how a heterotrophic protocell may have functioned."
Further, "Extrapolating from all the above data, inside fatty-acid vesicles the first self-replicating RNA molecule could have started copying itself. During copying, various things would have been possible. High-fidelity copies would have yielded the same self-replicating molecule. Copies with errors would mostly have resulted in RNA that was non-functional, but in a minority of cases, they could have yielded RNA that copied itself faster. It has been shown that RNA/vesicle systems that contain more genetic material (which would have resulted from faster RNA replication) develop more internal tension than neighboring vesicles that do not contain as much RNA, and draw membrane material from them. Importantly, this would have allowed for natural selection of vesicles by competition even in the absence of the ability to synthesize their own membrane components and therefore to directly control their own growth. Thus, for the first time, a system would have had the ability to undergo Darwinian evolution by natural selection acting on variation. This would have been a new and crucial emergent property arising at the transition from non-life to life.."
This process can be illustrated here:
Caption: "Conceptual model of a heterotrophic protocell. Growth of the protocell membrane results from the incorporation of environmentally supplied amphiphiles, whereas division may be driven by intrinsic or extrinsic physical forces. Externally supplied activated nucleotides permeate across the protocell membrane and act as substrates for the copying of internal templates. Complete template replication followed by random segregation of the replicated genetic material leads to the formation of daughter protocells."
From here, the evolution from protocell to modern cell was as simple as making the application of DNA and changing the structure a bit of the protocell to be more compatible for use in a multi-cellular organism. "In summary, based on available data a spontaneous origin of life as simple ‘cells’ containing a single genetic polymer, upon which natural selection could act, is feasible. A gradual evolutionary transition from these to common cellular complexity would have been possible."
creationtruth forfeited this round.
Creationtruth had his argument made out. Unfortunately, he did not submit it in time. Thus, we will simply skip defending our own arguments (originally planned for round 4). The new debate structure is as follows:
Con's round 3 - Present arguments
Pro's round 4 - Refute con's round 3 argument
Con's round 4 - Refute pro's round 2 argument
I ask that voters not penalize creationtruth for his mistake.
The cells of all organic life forms contain information in the form of genetic code. The chain of genetic code known as DNA harbors the amino acids which themselves contain no semantic meaning, but when placed in a linguistic sequence, can be readily utilized in forming every phenotype known to biology.
The living cell demonstrates a system of communication, particularly between DNA and proteins. DNA codes for proteins which go on to form every part of a creature, including the very DNA from which it was coded. DNA is a macro-molecule in the shape of a double-helix with a sugar-phosphate backbone.
The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder"s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.
An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell (http://ghr.nlm.nih.gov...).
DNA serves as the blueprint for every creature's phenotype. Since DNA is a language system in which communication occurs between a sender and receiver, it can rightfully be said to contain true information.
"To fully characterise the concept of information, five aspects must be considered"statistics, syntax, semantics, pragmatics and apobetics. Information is represented (that is, formulated, transmitted, stored) as a language. From a stipulated alphabet, the individual symbols are assembled into words (code). From these words (each word having been assigned a meaning), sentences are formed according to the firmly defined rules of grammar (syntax). These sentences are the bearers of semantic information. Furthermore, the action intended/carried out (pragmatics) and the desired/achieved goal (apobetics) belong of necessity to the concept of information (http://creation.com...)."
In the function of the genome within living cells we find statistics in the form of four letters which are syntactically organized to give the semantic meaning for transcription and translation. The semantic meaning encoded in the genome is pragmatically utilized in the formation of proteins and thus integral to the process of replication which is a part of the apobetic, or intended goal of the digital code.
Information intrinsically depends upon an original act of intelligence to construct it, therefore the information seen in living cells testifies to having been originally created by an intelligent Creator. Note that this argument is not based upon the inability for naturalistic/statistical processes alone to account for the formation of genetic information, but rather my case is built upon what we do know about genetic code and function. Therefore this is not a god-of-the-gaps argument, as the claim is based on observation. Not also that this is not an argument from complexity but from specified universal information. To refute my case is actually quite a simple task; one must only need demonstrate a single case where universal information, of the type seen in genetic code, is derived entirely from purely material sources.
Argument From Irreducible Complexity
The complexity of the cell alone is not what points to an intelligent Creator but it is the study of cellular function itself. For example, consider the superbly efficient molecular motor ATP synthase, a tiny protein complex which makes an energy-rich compound ATP (adenosine triphosphate). ATP synthase manufactures ATP from two smaller chemicals, ADP and phosphate. ATP synthase is so small that it is able to manipulate these tiny molecules, one at a time. ATP synthase must convert some other form of energy into new ATPs. This energy is in the form of a hydrogen ion (H+) gradient, which is generated by a different whole protein system to ATP synthase. Hydrogen ions pour through ATP synthase like wind through a windmill. This comprises a positively charged electric current, in contrast to our electric motors, which use a negative current of electrons (http://www.ncbi.nlm.nih.gov...). These rotary motors in the membranes of mitochondria (the cell's power houses) turn in response to proton flow (a positive electric current). Rotation of the motor converts ADP molecules plus phosphate into the cell's fuel, ATP. When a stream of tiny hydrogen ions (protons) flows through the base and out the side of ATP synthase, passing across the membrane, they force the axle and base to spin. The stiff central axle pushes against the inside walls of the six head proteins, which alternately become slightly deformed and reformed. Each of your trillions of cells has many thousands of these machines spinning at over 9,000 rpm (http://www.mrc-mbu.cam.ac.uk...).
ATP synthase is made by processes which all require functioning sources of ATP such as the unwinding of the DNA helix with helicase to allow transcription and then translation of the coded information into the proteins that make up ATP synthase. Manufacture of the 100 enzymatic machines needed to achieve this require ATP as well! And making the membranes in which ATP synthase sits needs ATP, but without the membranes it would not function (http://www.ncbi.nlm.nih.gov...). Evolutionists imagine how the ATP synthase motor might have evolved, but these are just surmisings, no conclusive evidence has been brought forth. This example of ATP synthase exemplifies the common chicken-and-egg problem many molecular machines exhibit. Which came first the ATP synthase which requires ATP or ATP which requires ATP synthase? This is quite a vicious cycle for evolutionists to explain.
Let us also consider the marvelous macromolecule DNA (deoxyribonucleic acid). DNA's function is to store and transmit genetic information, but it can't work without many molecular machines already inplace. However, as the noted philosopher of science, Sir Karl Popper commented, "What makes the origin of life and of the genetic code a disturbing riddle is this: the genetic code is without any biological function unless it is translated; that is, unless it leads to the synthesis of the proteins whose structure is laid down by the code. But '. . .the machinery by which the cell (at least the non-primitive cell, which is the only one we know) translates the code consists of at least fifty macromolecular components which are themselves coded in the DNA.' Thus the code can not be translated except by using certain products of its translation. This constitutes a baffling circle; a really vicious circle, it seems, for any attempt to form a model or theory of the genesis of the genetic code. Thus we may be faced with the possibility that the origin of life (like the origin of physics) becomes an impenetrable barrier to science, and a residue to all attempts to reduce biology to chemistry and physics" (https://books.google.com...).
Richard H. Ebright and his team from Rutgers University have discovered more intricacies in the process of transcription (http://phys.org...), where information from the right-part of the DNA is copied onto a strand of messenger RNA (mRNA). It is this mRNA that is translated into proteins in the complex machines known as ribosomes. DNA is double stranded, so must first be unwound, so that the right strand can be copied onto mRNA, in a sense like a photographic negative. So one of these machines (ribosomes), called RNA polymerase (RNAP), first locks on to the start of the gene. The next stage is that the anchored RNAP then reels in the DNA which unwinds the double strand so that the messenger RNA copy can be formed off one of them (http://www.sciencemag.org...).
A problem arises for abiogenesis in the following way: the instructions to build RNAP are themselves encoded in the DNA. But the DNA could not be transcribed into the mRNA without the elaborate machinery of RNAP. And this is also an example of irreducible complexity because it would not be able to perform its function unless every feature was fully functioning. There would be no use being able to dock onto the right spot of the gene and getting stuck there, or unwinding the DNA without being able to wind it back. Furthermore, RNAP uses ATP as an energy source to achieve its feats. And ATP is made by, of course, the ATP synthase which is also coded on the cell's DNA. Therefore, until RNAP is fully formed, coding for cellular instructions would not be possible as the process of transcription into mRNA requires RNAP.
I would like to thank creationtruth for presenting his arguments.
Argument From Genetic Information
I actually already explained the majority of what is required to refute this argument in round 2. I noted how ribonucleotides (i.e. adenine, guanine, cytosine, and uracil) could have formed on the conditions of the early earth, how individual ribonucleotides could form into long strands into RNA molecules, and how these molecules could have become the nucleus for a protocell. "Importantly, the starting materials for the reaction can utilize starting materials that are considered prebiotically plausible, and provide high yields of RNA nucleotides."
Unfortunately, we have not synthesized a molecule of RNA next, all the steps are already there, so much so that there have been studies providing methodologies for doing so. This isn't a concession - we simply just haven't developed the science to synthesize RNA. But we have built the building blocks and found applicable catalysts. All thats left is to conduct the research properly.
The claim that DNA is information is a misnomer. DNA is a molecule, like water. There's nothing special about DNA that gives it information but not water. DNA only contains information in the sense that a particular strand of it corresponds to a unique genetic state. It's not information contained in the DNA. We can only infer certain information from the DNA, in much the same way that the fact that water freezes at 273.15 degrees K is not information contained in the water - it's only information that we attribute to water.
If DNA were information, we'd expect small deviations in the strand (i.e. exchanging two nucleotides) wouldn't significantly change the molecule's effect, although we know that's not true (think mutations). Further, while DNA can replicate, there is no example of information replicating. The information stored on your computer in the form of electrical signals stored on your hard drive don't simply replicate out of nowhere.
All the necessary information that we attribute to DNA was already there on the early Earth. "Nothing needs to assemble itself. Evolution and abiogenesis do not exclude outside influences; on the contrary, such outside influences are essential. In abiogenesis, it is observed that complex organic molecules easily form spontaneously due to little more than basic chemistry and energy from the sun or from the earth's interior. In evolution, information from the environment is communicated to genomes indirectly via natural selection against varieties that do not do well in that environment."
Thus, it has been shown how RNA could have been created (and thus, later on, DNA) from building blocks that have been shown to have been created on the conditions of the early earth. Further, DNA is not information itself - we only attribute information to DNA. All the necessary information was already there.
Argument From Irreducible Complexity
Before I begin to refute my opponent's arguments directly, this argument has several immediate problems. First, it's not falsifiable. We can't test that the argument from irreducible complexity is false, because it bases its theories on the interpretations of other studies instead of positing studies itself to test the theory. The only evidence for it is the non-existence of naturally occurring irreducibly complex systems. This makes the irreducible complexity theory psuedoscience.
Second, it's fallacious - it's based on an argument from ignorance (the very fallacy my opponent cautions against in his first argument). Just because we have not been able to produce naturally occurring irreducibly complex systems does not mean that they don't exist, or that we should immediately claim supernatural causes behind such systems.
Beyond that, the argument from irreducible complexity doesn't prevent as many things as my opponent thinks it does. "Irreducible complexity can evolve. It is defined as a system that loses its function if any one part is removed, so it only indicates that the system did not evolve by the addition of single parts with no change in function. That still leaves several evolutionary mechanisms:
All of these mechanisms have been observed in genetic mutations. In particular, deletions and gene duplications are fairly common, and together they make irreducible complexity not only possible but expected. In fact, it was predicted by Nobel-prize-winning geneticist Hermann Muller almost a century ago. Muller referred to it as interlocking complexity.
The ATP synthase example is actually an example of modular evolution, where two previously functionally independent subunits became associated and gained new functionality. The idea is described thus: "The modular evolution theory for the origin of ATP synthase suggests that two subunits with independent function, a DNA helicase with ATPase activity and a H+ motor, were able to bind, and the rotation of the motor drove the ATPase activity of the helicase in reverse."
As for the RNAP/DNA example, I unfortuantely cannot seem to find any scientific literature on the subject, which is a shame. However, this doesn't mean that this argument refutes abiogenesis, because of the inherent problems with the argument from irreducible complexity discussed above.
creationtruth forfeited this round.
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