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Re: Evolution

Thomas Brenndorfer
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SubjectRe: Evolution
FromThomas Brenndorfer
Date2002-04-11 07:44 (2002-04-11 07:44)
Message-ID<Zo9t8.4403$ZiL.996@news02.bloor.is.net.cable.rogers.com>
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Newsgroupsalt.fan.tolkien
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Joy
Whoa. We know microevolution and evolution within species occurs, but macroevolution involving a species-level change in genetic code has yet to be documented as "fact", I believe. If so I must've missed it. It isn't a "fact".

I know that. I just don't accept *anything* as fact. There is no evidence at all for abiogenesis, the fossil record for evolution is sketchy at best, nobody can thoroughly explain the evolution of wings, feathers, or avian flight, and as those on this thread have said, the actual mechanism of evolution is a mystery. Very few things are actually "fact", and macroevolution is certainly not one of them. The "fact" that the universe is infinite is *not* a fact, just conjecture based on what evidence people have gathered. (Although if we accept some views on the avian-evolution debate... Gandalf's balrog *had* wings... gradually evolved after its ancestors died from falling.)

Every day more and more evidence is being accumulated about the facts of evolution and its basis in genetics. Evolution is simply a numerical rate-- the change in the frequency of alleles (i.e., genes) in a population. That this frequency changes has been proven in many cases, particularly with rapidly reproducing species such as bacteria-- a mutation eventually appears and if it is beneficial, the bacteria that carry it multiply and dominate the population. This is of course of particular concern with antibiotic-resistant bacteria. New strains of HIV are appearing as well. These facts of evolution are of pressing concern in the treatment of diseases, and many new therapies, especially with AIDS take into the account the nature of the evolution of the virus and so a balanced, composite approach is used (too much of one drug will drive evolution even faster, resulting in a worse situation over time).

Speciation is simply when a population has split into groups and reproduction becomes impossible between those groups over time. But even this is a slippery definition, since some species can reproduce with other species that were separated a long time ago, although the result is often sterile offspring. One of the mechanisms for evolution is natural selection (all dogs we see are the result of "artificial selection" by man in that the vast variety of breeds all were descended from a single group-- cats, especially wild cats, on the other hand, are the result of the speciation process of natural selection). One can easily imagine a population split into groups with each group ending up in a different environment. Over time, the characteristics of those groups would show differentiation (reflecting the change in allele frequency). In cold climates, the surviving members of the group would likely have characteristics better suited to that environment, and these in turn would produce more offspring, and so on, and so on, resulting in a greater set of differences from the earlier related groups. At some point interbreeding stops, but it actually may start again if the groups are brought back together-- which may result in even more wild and crazy genetic recombinations. Scientists have studied the finches on the Galapagos Islands over the decades, and have seen this fluctuation in what characteristics dominate in a species-- the drive to adaptation was clearly seen in that the changing environment would favour some individuals with certain characteristics and only these would survive to produce offspring. Each generation would have different average characteristics from the previous generation. Groups would form, and interbreeding would stop, at least for a while. Many people in the 19th century other than Darwin were slowly coming to the same conclusion. Species on relatively young geological formations (such as islands) were similar to species on the mainland, but clearly had different characteristics and many could no longer interbreed with the mainland groups. There were no species wholly original to the islands-- all seemed related to mainland species. How could this happen? These were the facts people had to contend with, and there was no dispute over the facts except from those who refused to look at the facts of what was called evolution. The numerical proof of genetics and allele frequency for macroevolution came later.

The logical conclusion from all this is that all life shares a common history-- a descent from a common ancestor. Many of the same genes appear in all living creatures. And more and more models of the genetic basis for evolution are being discovered. For example, a common resource that evolution uses is the mutation that results in a copy of a gene alongside the original gene. The original gene continues its business (producing proteins for X purpose), but the new gene can branch out over time into other specializations with further mutations. An example of this is the gene that allows cows to digest grass. This gene is derived from a copy of a gene that is used to fight bacterial infection. This same genes appears in many animals. Cows are lucky in that they get to keep the original gene and can make use of the newer gene to exploit more food resources such as difficult-to-digest grasses. That beneficial mutation resulted in morphological changes over a long period of time that can be seen in the fossil record-- the implication is that the ancestor of the cow was not very good at digesting grass. Some animals have undergone the same mutation, but the original gene mutated, not a copy. Koala bears are an example, in that they can digest difficult plants, but they are susceptible to certain kinds of bacterial infection since they no longer carry the original gene for fighting those infections, only the mutated one.

I used to share the same skepticism you have about evolution. However, I rejected the statements that creationists made since I observed that most of what they were saying were rhetorical tricks. They kept repeating the same lies even after the evidence was presented. They kept on making "straw man" arguments, essentially making their own (ridiculous) claims about what evolution is and then tearing them down (which was easy to do, since their claims were manufactured and bore no resemblance to what evolutionists actually thought). They continued to make the same claim (microevolution yes; macroevolution no) even when it could be clearly demonstrated what scientists studying evolution are really dealing with. They trotted out various statements from "authoritative" figures, some from the evolution community, but these were all shown to be taken out of context. They claimed any argument about the process of evolution amongst evolutionists is proof the whole thing is a sham, even though this is the same strenuous peer-review process that all science undergoes (a process of rigourous testing which they reject for themselves and their claims, since their belief system absolutely requires Creation, Adam and Eve, original sin, and the redemptive act of Christ, the latter of which is rendered less meaningful if the Bible is incorrect about its depiction of the origin of life and species). And of course these are the same people fighting to bring creationism into the science classroom, often using stealth tactics such as stacking school boards, instead of demonstrating any scientific basis for their beliefs, apart from rhetoric-filled books and pamphlets, which use all the buzzwords, but do not follow the scientific method. As the Pope said: "Evolution is more than a hypothesis".

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Joy (3h & 52m)