[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Morpho v molecular (was Re: Tinamous: living dinosaurs)

 This brings to mind something else that concerns me. Are molecular
 phylogenies tested and re-tested by the addition of new taxa (when
 possible) and/or new sequence data until the tree "looks right".

The former. Work on placental phylogeny didn't end in 2001, that's when it started in earnest.

Come on. "They" are not more intellectually dishonest than "we".

 But what if the whale/hippo/ruminantian clade is also "wrong"? How
 would we know? If we've exhausted the option of taxon sampling, is
 stringing together even more gene sequences going to resolve the
 problem if the gene sequences themselves are the problem?

Wouldn't then particular gene sequences which evolve too quickly or whatever be the problem?

It goes without saying that different genes sometimes tell different stories. Metaves/Coronaves is perhaps the most famous example on this mailing list.

 With turtles, I think we've hit a wall in relying on molecular-based
 phylogenies to tell us where turtles came from. IMHO, the fossil
 record is our only hope.

Here, too, I think it's actually the lepidosaurs that are misplaced in most molecule-based phylogenies, not the turtles. But you're right, the potential taxon sample for molecule-based analysis is limited in disquieting ways.