the phylogeographic challenge to creationism

Sorry, yes you were answering the OP. No, variation is the result of normal reproduction which shuffles alleles into new combinations, at least in the case of sexual reproduction. Mutation does not have to enter into it.(I started calling these processes subtractive and additive to make my basic point about them clear).This message has been edited by Faith, 12-08-2005 02:39 PM

With regard to my responding to the OP, no problem.With regard to the variation, what creates the alleles themselves and maintains their diversity is mutation. In any case, I learned a bit more by responding to you, and hopefully my response will provide a clearer picture for some other people. At the same time, I am looking forward to seeing the responses of some others -- haven't had the time to as of yet, but I am sure I will learn even more.Time to go feed the crows...

Yes, so I understand, but when I am using the term I'm not thinking of mutation, merely the usual Mendelian process of variation. I hope to have time to answer your post more fully later. Just wanted to make that one correction as I saw it.

No problem.However, one point I would like to emphasize (before it gets lost in the allele shuffle) is the fact that there has been an overemphasis upon the role of genes in evolutionary theory up until the past few years. Mutations in genes are important, of course, but it is the regulatory DNA which appears to be most important. The proteins and genes we use aren't really that much different from those of any other eukaryote -- it is how the proteins are put together into a living organism which seems to matter most.From: Message 226, (Point #9) This message has been edited by TimChase, 12-08-2005 09:03 PM

Mendelian sexual recombination doesn't actually constitute a source of variation, though - it's only an explanation for patterns of variation.For instance, Mendel's models explain how much of a population of pea plants will be tall, and how many will be short. They do nothing to explain where the "tall" and "short" traits actually come from. For that, mutation is required.It really doesn't make any sense to examine variation in the absence of mutation, although I understand that you're tenaciously attempting to do so because the very existence of mutation completely undermines your argument.

Just going to point out that this was addressed in point #6 in post 240: Message 240 (which deals with Kimura's neutral theory of molecular evolution).

Wow -- I hadn't ever heard of this...[looked it up, editing this in within the box directly below -- consider this a case of lateral transfer] Reminds me of what they discovered with the hothead plant. Scientists bread a version of hothead which was missing a given allele, and the following generation the allele turned up again. Some thought that an RNA transcription of the missing allele might be hanging around, but it turned out that the gene was hypermutative. Of course, the example involving the bacteria reaquiring removed functions is even more dramatic in some ways -- although no doubt it had a larger population and more generations to play with.For an article on the hothead, see one of my favorite nonfiction authors:Stay Right There, Mendel
by Carl Zimmer
November 3, 2005
http://www.corante.com/.../11/03/stay_right_there_mendel.phpOh, and I have mentioned another couple of examples of hypermutation -- two that hit particularly close to home for our species: Message 240, point #6This message has been edited by TimChase, 12-08-2005 10:21 PM

I remember a while back looking at some old conversation between genetics students at this site regarding lateral gene transfer -- and I believe origin of endogenous retroviruses (RNA viruses which reverse transcribe themselves into a host's genome as proviruses, get stuck, and then passed from generation to generation). One viewpoint I was rather sympathetic towards was that the insertion counted as a form of heredity -- where the ancestor was the original, infectious exogenous retrovirus. But technically, from the perspective of genetics, it is interpretted not as a form of heredity, but as a mutation in the host genome.

Right. Of course, if the host reproduces and passes along the retroviral insertion to its progeny, that is heredity.It is my understanding that even movement of a transpositional element already present in the genome is considered mutation.

(emphasis added)"Enjoyment" is really the key. There are a great many games being played on the internet. I believe Faith's is a zero-sum -- like the good majority of them. However, the most interesting games are positive-sum....

LOL, so I am more closely related to any number of viri than I am to a chimp. In fact, it is possible I have 3 or more parents. I like that thought.It is almost as good at the factino that I am 90% not me but rather bacteria.

Wow, what if we aren't chimps at all then? What if we were originally some sort of super-intelligent velociraptor types who got a bunch of uh, retroviruses from chimps, by you know Doin It with them, thinking it would be Safe ("No eggs in this one," said ZZaxx, slapping her hairy thigh)and so now 50 million years later, we have a rule about that stuff but it's way too late, we're chimps, wages of sin and all that.Just a theory

Oh. My. God.(welcome, by the way.)

Shouldn't that be "feathered thigh"? (Or maybe not...after...)I know that sounds like a quibble, but I really just wanted to see that passage in print again.Welcome.

Do you have a reference? I know that there have been a couple of alternative hypotheses put forward (Comai and Cartwright, 2005; Chaudhury, 2005), but I was unaware that there was definitive research on the subject.TTFN,WK