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Debate: 15 questions for evolutionists (view source)
Revision as of 08:24, January 25, 2012
, 08:24, January 25, 2012→What an evolutionist would say
::Agreed, the origin of life is a biochemical question--not really an evolutionary biology one. --[[User:JHunter|JHunter]] 12:36, 21 January 2012 (EST)
::Agreed, the origin of life is a biochemical question--not really an evolutionary biology one. --[[User:JHunter|JHunter]] 12:36, 21 January 2012 (EST)
::::That said, most of modern biology consists of biochemical questions, including the major mechanisms underlying evolution, so the question on the origin of life is not an inappropriate one here. To answer it, I must first address an idea that I've heard quoted by creationists addressing this question in the links provided by User:Conservative. That is the common misconception that the current scientific consensus suggests that life started as self-replicating polypeptides. In light of evidence uncovered in the past couple decades, this hypothesis is now considered highly unlikely; the process that would become "life" was likely already started before the "primordial amino acid soup" came into play. Self-replicating polydeoxyribonucleotides (DNA strands), are also considered an unlikely because of the chemical characteristics of DNA. Self-replicating strands of RNA, on the other hand, can be randomly generated in a laboratory using common, non-biological, reagents. This is a far-cry from the long-discredited Miller-Urey experiment (their experimental conditions turned out to be a wildly incorrect reproduction of the early Earth), that found organic molecules in a solution zapped with electricity. Besides, complex organic molecules seem to form spontaneously (albeit in trace amounts) wherever the right elemental ingredients are present; that's the age-old rule of organic chemistry, if a side reaction '''can''' happen, it '''will''' happen to some degree.
::::Life is chemistry, very complex chemistry, but it is still chemistry. The components of a cell consist of biomolecules behaving in a chemical way (drugs are designed to take advantage of this fact). Barring any philosophical discussion on the meaning of life (for the last time, '''the answer to life, the universe, and everything is 42'''), the purpose of a cell (or a complex organism consisting of a vast network of cells) is to reproduce. Self-reproduction is one of the defining traits of life. Ribonucleotides (present in trace amounts wherever the ingredients are found) will spontaneously form 5' to 3' polymers in a warm, reducing, aqueous environment; such as that found around the edges of a hot-spring (assuming a low oxygen atmosphere, which is unanimously suggested for the early Earth by geological data), or even an oceanic thermal vent. That one or more of these oligomers would have the enzymatic capacity to self-replicate is extremely plausible. When considering the scale (an entire planet), it becomes probable.
::::How these self-reproducing RNA strands started conspiring with amino acids, became compartmentalized in phospholipids, and then started using a DNA template, is still largely unknown. It is thought that these changes occurred in the order I just mentioned because that is the most chemically plausible order of events; although a plausible scenario is still very far from an established theory. As more evidence becomes available, as more experiments are done, and as geology reveals more information about the chemistry of the early Earth, it is likely that the scientific community will arrive at more of a consensus regarding the origin of life. Obviously, nobody was there to witness the origin of life and, unless the NSF allocates grant money towards a 1981 DeLorean, a conjectural consensus (that is well-supported by all the evidence) will be the closest that science can come to providing an answer to this question. This does not mean that scientists "don't know"; in the absence of first-hand observation,an inference from evidence is the closest that the scientific process can come to explaining anything.
::::There is evidence that much of the Old Testament (after Genesis) is a historically accurate, if poetically embellished (as all histories were at the time), account of bronze-age Jewish history. Archaeological evidence supports this and so science supports this. However, it is a non sequitur to conclude that because ''some'' Old Testament stories are grounded in historical fact that ''all'' Old Testament stories are literally true--even St. Paul admits that this is a matter of faith (and open to interpretation), not evidence. To draw an analogy, Livy, a Roman historian, wrote a lengthy account of the history of the Roman people. Much of this account is very historically accurate and is supported as such by archaeological evidence. However, it is very clearly illogical to conclude that because Livy's historical narrative is largely true, his references to the Roman gods playing a hand in these events must be true as well. Similarly science, which by definition can ''only'' rely on empirical evidence, must search outside of scripture for evidence regarding the origin of life and draw conclusions based on evidence alone. --[[User:JHunter|JHunter]] 03:24, 25 January 2012 (EST)
===What a creationist would reply===
===What a creationist would reply===