Evolution: common descent not shown by genetics (Introduction)

by dhw, Monday, January 29, 2018, 13:53 (2489 days ago) @ David Turell

DAVID: Studies of DNA at various levels of evolution do not fit common descent:
http://nautil.us/issue/9/time/evolution-youre-drunk

Thank you for this very important article. It certainly knocks on the head your hypothesis that evolution advances through a drive to complexity, but it also requires a wriggle from me to adjust my own hypothesis. First, though, a correction:

QUOTE: "The idea of directionality in nature, a gradient from simple to complex, began with the Greeks, who called nature physis, meaning growth. That idea subtly extended from changes over an organism’s lifetime, to changes over evolutionary time after Charles Darwin argued that all animals descend from a single common ancestor."

Darwin: “There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one…” The alternative “few forms” is important in the context of this article.

QUOTE: "Casey Dunn, an evolutionary biologist at Brown University in Providence, R.I. who took part in the still-contentious comb jelly project, now doubts all notions of increasing complexity. Instead, he says the environment selects whatever form handles the challenges at hand, be it simple, complex, or plain ugly. Mother Nature, with her 4 billion years of experience, does not work like Steve Jobs, continuously designing sleeker versions. When asked whether de-evolution, a reversal from the complex to the simple, happens frequently, Dunn replies, sure. “But,” he adds, “I wouldn’t call that de-evolution, I’d call it evolution.'”

DAVID's comment: This is a Darwinist showing her prejudice. DNA does not support common descent, but she can't think of it as God guiding. I've had to skip many of her examples of evolution running backward.

Casey is a “he” apparently. Please forget your prejudice against Darwin and in favour of divine guidance for every evolutionary development, and focus on the argument. A few original forms, as opposed to one, solve the problem at a stroke: some were simple and some were complex, and so there are different lines of descent. But Dunn’s link with the environment is crucial. Reversal is nothing new. Darwin regards vestigial organs as evidence for common descent, and this might give us a clue as to how the whole process works. All organisms MUST be able to cope with their environment, and there is no reason why this should necessitate increasing complexity (think of bacteria). As each organism finds its niche, it may add or delete accordingly. My own hypothesis (evolution is driven by the quest for survival and/or improvement) needs to be tweaked, because the same quest may lead not to innovation but to regression, which would result from a response to particular environmental conditions. Complexity in itself is therefore irrelevant: the decisive factor is change that will improve the organism’s chances of survival and/or way of life. Once cells joined themselves into communities, they had an almost infinite potential of forms – some simple, some complex. Hence the ever changing bush, with organisms coming and going, complexifying or simplifying, as they coped or failed to cope with or exploited the ever changing environment. Why must God guide it all? If he exists, he would have invented the mechanism that gave rise to this vast potential and hence to the ever changing bush.