Lucy in Newsweek
kinman2 at YAHOO.COM
Fri Apr 2 21:54:19 CST 2004
An interesting argument, but I think it is problematic in that biological parasites (whose phylogenies you refer to) do not create their hosts. If one wants to regard DNA as a parasite, fine, but it is a very special case in which the parasite creates its own host. Therefore one would still expect the phylogenies to be congruent.
Like Curtis, I find it hard to understand why anyone would suggest that evolutionary history leaves traces in morphology, but not the genome. It just doesn't make much sense if you think about it long enough. Obviously not all genetic information is going to be phylogenetically informative, but some of it certainly is. It's just a matter of separating the wheat from the chaff (and the same is true for morphological data). If John hasn't been able to find molecular evidence for this hypothesis, then he should just keep digging for it. Arguing that it is probably irrelevant does not sit well with me at all. In much the same way, it does not sit well with me when he fails to include Antarctica on his pangeographic maps for groups that probably occurred there before Antarctica froze over. That they no longer occur there does not justify completely leaving Antarctica off such maps. Such approaches just feel to me like wearing blinders and thus hamper useful speculation where it is needed.
From: HJJACOBSON at AOL.COM
In a message dated 4/2/2004 8:04:37 AM Pacific Standard Time, jcclark at CSUPOMONA.EDU writes:
> Perhaps "overall similarity" is not the best measure, but I can't believe that you are suggesting that evolutionary history leaves traces in the morphology, but not the genome.
I should like to ask a question, and I mean ask. If the "selfish gene" view were taken, couldn't DNA be viewed as a parasite? Now studies of parasite and host phylogenies show that they are not always congruent. Tree topography and rates may differ between parasite and host. Differ enough, I believe, that you can't derive one from the other. It isn't always a case of coevolution. Again, assuming the "selfish gene" wouldn't be more conservative to conclude that genetic phylogeny isn't necessarily the same as species phylogeny, as John has suggested? OK, it's two questions.
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