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Posted by WW on November 27, 2002 at 03:35:26:
In Reply to: Re: more importantly.... posted by vvvddd on November 26, 2002 at 23:18:06:
:so in summary (from this discussion):
:1) The species are probably not truely separated groups
:2) The data (from the obsoleta/allegheniensis study alone) suggests *some* cladism within the entire group based on one gene
The number of genes is not really all that important, given that the entire mtDNA molecule is inherited in one piece, as a single linkage unit. If the phylogeentic pattern is clear and robust enough in one gene, then that is probably all you need. How this mtDNA phylogeny relates to the organismal phylogeny, and how relative it is to the genetic structure of these populations when nuclear markers are concerned is another question, and one that lies at the heart of the itnerpretation of these papers
:3) Studies based on molecular and morphological data are more reliable
:But, does he successfully refute the subspecies? Based on his data (alone), I'd have to say it does. I'd like more proof though.
He certainly has shown (in the E. obsoleta study) that the subspecies bear no relation to the matrilineal phylogenetic history of these populations. Moreover, in the morphological study he published on the E. obsoleta comple, he also showed that morphology was more closely associated with the mtDNA phylogeny than with the conventional sspp. I would regard the connventional subspecific arrangement of E. obsoleta as sunk without trace. What we don't have is a well-substantiated new classification.
:Also, what does convergence (as far as color/appearance) add to this? The suggested clades would imply that the groups converge to darker phenotypes as they go further north. Is this not a factor at all or is it just unlikely? Due to gene flow?
Good Q - could be either convergence of gene flow - there might be rampant nuclear gene flow across these mtDNA clades, or melanism may have evolved convergently at high latitudes. A study using nuclear markers (microsats, AFLPs) would tell us more.