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Re: turning turtles
At 01:28 PM 2/24/99 +0000, John V Jackson wrote:
>>To summarise, the maximum likelihood phylogeny, based on 11 nuclear
>>proteins (1943 amino acids) was:
>>(Rodents + Primates) + (Squamates + (Birds + (Crocs + Turtles))).
>>Tuataras weren't included due to lack of data.
>Proteins behave differently at different temperatures. Warm-bloods might be
>expected to have protein strucutres that worked well over a limited range,
>but "cold"-bloods probably have pressures converging their proteins to
>optimum behaviour over a wider range of temperatures. I would expect a
>clustering effect inside groups with similar thermal modes.
There is another factor that *may* be relevant here - long branch
attraction. There is considerable time depth back to the
lepidomorph-archosaurimorph split, and (in the traditional cladogram) an
even *longer* time depth to the split of the chelonians.
[The same problem may be showing up in the studies that link whales to hippos].
May the peace of God be with you. firstname.lastname@example.org