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Re: A Wild Hare [not dino related]



Are molecular studies proof? Or evidence?

Evidence.

Of course, if several genes agree, which is the case with bat monophyly (every placental phylogeny study has included both micro- and megabats), then the evidence becomes much, much stronger.

Some bat-centered molecular studies use impressive numbers of taxa.

And what is the final measure in head-to-head competition.

Final measure? In science? ~:-|

Pettigrew et al. gives a really convincing account, including reams of
soft tissue data that is well worth a read.

Yes, but to me it reads sort of like the classic method of "cladistics with one character". Have they really checked the precise distribution of these features? They say microbats lack them, megabats have them, and primates have them, and don't seem to mention anything else.


They also put great emphasis on the differences between micro- and megabats while neglecting the synapomorphies.

Finally, the whole thing is a bit old. I dimly remember a morphological study that found bat monophyly... is that false memory?

Long answer:  Recent molecular studies have thoroughly refuted the
hypothesis that bats are diphyletic, with megabats closer to primates.
Last I heard, molecular evidence was even indicating that
Microchiroptera is actually paraphyletic with respect to
Megachiroptera,

Yep. That's the one with the many OTUs.

and that bats are on a totally different branch (no pun
intended) from primates on the placental tree (hanging out with shrews,
true ungulates, carnivores, and pangolins).

Old news (2001 at least).

>> In the above paper is a ref [not copied] for some soft-tissue
> cladistic work describing a close association between lagomorphs and
> primates.

Interesting.  Molecular evidence also indicates that rabbits + rodents
are close to primates + tree shrews + colugos.

Plus, there are lots of Paleocene fossils that only fit around the rabbit-rodent divergence.


> 1. Do eurymlids have a large diastema like Gomphos, lagomorphs and
> rodents do?

Not familiar with them.

They seem to be known mostly from teeth; I only found this abstract http://www.bioone.org/bioone/?request=get-document&issn=0272-4634&volume=021&issue=03&page=0565 talking about bones.


> 2. I know that a basal primate, Plesiadapis, has a large diastema,
> among other interesting characters.

May not be a primate; possibly closer to dermapterans,

Where exactly the plesiadapiforms lie is still not clear, but they're the sister-group either to (the rest of) Primates or to (the rest of) Dermoptera. (Dermaptera are the earwigs!)


though (AFAIK) still an archontan.

Euarchontan, yes. (Archonta was the hypothesis that bats -- as a whole -- are related to Primates + Dermoptera + Scandentia, based on eye anatomy and I don't know what else.)


> 3.  Did the two large diastemas, so close to each other on the tree,
> develop convergently? Or is there another connection?
>
> And in a worst-case scenario, wouldn't that be weird?

Not really.  Highly related to food processing; diastemata appear to
have arisen many times among mammals.

Yep. And, for that matter, in hadrosauriforms, ceratopsians, and I forgot what else. If teeth are not needed between the tip of the jaws and the positions closest to the jaw joint, they are lost.