More Evidence of Evolution - Geomyidae and Geomydoecus

Could the word “random” have a psychoactive effect on MartinV and his ilk? Something like "heathen" or "godless"? He might read “random” as “not by the hand of God,” which of course offends his faith. Everything said afterward about Darwinism is essentially blocked out by this attitude.But whose fault is it? I think MartinV and his ilk are understandably confused by the confusion amongst evolutionary biologists about the role of random mutations as they relate to natural selection. Here’s one measure of importance attached to mutation: What is confusing here is the implication that natural selection always requires random mutations to enable an evolutionary event. This explanation ignores the role of exaptation”alleles and genes already carried in the genome, remaining unexpressed until favorable changes of circumstances allow for their selection. Gould, for example, reasoned that the genetic potentials for exaptation may actually account more for the evolution of certain species than random mutations.So the notion of potential takes on new meaning. And those exapted genes and/or alleles do not have to come only from mutations”some find their way into a genome by way of horizontal DNA transfer, also viewed as gene flow.Maybe MartinV might be more comfortable with Darwinism his he saw that genetic potentials were often causal in the course of evolution. Then he could always say: Hey, look, if there are potentials then they can be seen as evidence of ”the hand of God.’”HM

Tsetse flies, maybe? Do you consider HGT a form of mutation?

Well, they might already be expressed when exaptation takes place. Let me try this hypothetical scenario:There are two alleles that express the inner ligament protein of the human thumb. One is a dominant allele, which is not as flexible as the other allele and prevents the thumb from curving backwards into a “hitchhiker” position. The other allele, the recessive one, produces a more flexible ligament, permitting the thumb to curve backwards into the so-called “hitchhiker’s thumb” position.Right now, neither allele plays any role in selection, so far as we know; the gene is evolutionarily neutral. But let’s say something changes, something that would benefit the recessive hitchhiker’s thumb allele. Let’s say it assumes a sexual advantage”mate attraction, perhaps”so that those humans with hitchhiker thumbs are reproductively favored over those who don’t have them. Here would be a case of exaptation accounting for a selection advantage without the need for mutation.”HM

That bad, ay? How can you say that after writing this stinker in post #32?: What’s this? Natural selection "selects individuals”? Do you actually believe that natural selection operates at the level of the individual? I don’t know of any credible biologist who thinks natural selection selects individuals.This is a good example of how people like MartinV get confused about the Darwinism. You have other concepts confused, too. For example, many good neo-Darwinians will dismiss "convergence" and "parallelism" on the grounds that "deep homology" can acount for the same effect. Furthernore, there are no "proofs" of convergence, not when you consider the alternative explanations.What do we expect MartinV to take from all of this confusion? He would be better served if we took our Occam's Razor to some of this evo-devo fluff. And if the word "random" is a bother for him, then he might take comfort in knowing that selfish genes have a distinctively non-random attribute: they deterministically adopt strategies for survival. Hamilton and Dawkins have provided much more "proof" of that than what is claimed to be "proof" by the evo-devo advocates.”HM

MartinV, maybe it would help if you understood that “random mutations” are not the only way that evolution can happen. Evolution can also happen when:1. a subject population's size drops below a level where random genetic drift cannot be avoided,2. genes and/or alleles from external populations enter the subject population’s gene pool,3. all individuals of the subject population do not have equal access to mating, and4. all individuals of the subject population do not have equal success in reproduction.Given those requirements it’s a wonder that any species lasts very long. But I suppose the human species measures time on its own scale.”HM

Frog, you're living in The Dark Ages.

Yes, perhaps a new thread is more appropriate, because “group selection” and “individual selection” need to be differentiated from “gene selection” and “kin selection.” It must be confusing to MartinV and his ilk that Darwinian biologists can’t agree on exactly what natural selection is and where it occurs. And, unless you invoke the selfish-gene theory, the same quandaries can be raised about evolution itself.By definition, natural selection is the possible consequence of uneven reproductive success of individuals in a population. But this does not mean that natural selection necessarily operates on the individual or its population, even though the results may occasionally point in that direction. Looking closer, as did G. C. Williams, Wm. Hamilton, R. Dawkins, et al., the actual site of natural selection can often be seen at the level of genes and their alleles (i.e., genetic evidence of strategic altruism for kin survival). “Group selection” and “species selection” (i.e., 'for the good of the group or the species') are no longer regarded as credible by most biologists, although some still claim them to be true. Furthermore, natural selection is not the only cause of evolution (as I have already taken pains to point out). Non-selective agencies like genetic drift, gene flow, and preferential mating may also cause evolution to occur.I know crashfrog will be bent out of shape because we’re not taking about his mice and lice and parallel convergences. So maybe another thread is needed to discuss the question ”What exactly is natural selection and precisely where does it occur?’”HM

1. Preferential mating is a non-selective agency of evolution; it is not the same thing as natural selection.2. I've proposed a new topic 'What exactly is natural selection and precisely where does it occur?' So, I won't be bothering you and your mice and your lice and their parallel convergences anymore.”HM