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Re: origin of bats/suspect trees? (combined answer)



The fossa has prehensile thumbs and carries stuff? I had no idea...

----- Original Message -----
From: "David Peters" <davidpeters@att.net>
Sent: Friday, June 20, 2008 4:11 PM

> The outgroup taxa used were Tupaia (tree shrew), Erinaceus (hedgehog), > Sus
> (pig), Felis (cat), Cynocephalus (dermopteran), run either as > unconstrained
> outgroups or constrained to a molecularly-based topology.


The problem here is twofold:

1. The outgroups are really way out. Closer outgroups have not been DNA tested.

None of the above is closer than the cat. Closer outgroups may be known, but no DNA can be known from them because they're Paleogene fossils...


2. The authors state: "Because morphology based phylogenies of extant bats conflict with those based on gene sequences..." So...until DNA tests support morphology and vice versa (we can see the same problems within the Reptilia where even DNA testing does not agree with other DNA testing), DNA tests among varying genera will always be suspect. Within genera, the evidence is stronger as any CSI TV show will testify. And occasionally DNA gets lucky.

It is _painfully_ obvious that you don't have the slightest idea what you're talking about. You have even stooped to the genericometer fallacy! Argh.


----- Original Message -----
From: "David Peters" <davidpeters@att.net>
Sent: Friday, June 20, 2008 8:05 PM

If the taxon lists are the same using morphology, the tree results will be the same, if you employ at least 150 characters. Thatâs the bottom line. Thatâs always been the bottom line.

For how many taxa? 20?

Doesnât matter which characters. Delete cranials. Delete post-cranials. Delete axials. Delete every other character, or every tenth. If you test like this, youâll see what I mean.

Either data matrices of tetrapod phylogeny are utterly abnormal (delete postcranials and get phylogenetic grass!), or what you say is utterly unrealistic.


Getting back to bats: At least we should be looking for non-volant mammals with SOME bat characters, like broad flat ribs, reduced distal ulna, pedal proportions, wrist fusions, tooth counts, tooth shapes, etc. Funny thing is, there are such creatures, and they are arboreal, theyâre just not cats, pigs and hedgehogs.

This is not at all surprising.

A reduced distal ulna comes with elongate forelimbs. Almost inevitably.
Pedal proportions -- climbing.
Wrist fusions -- all over the place. Isn't there individual variations in humans in whether the centrale fuses to the 3rd distal carpal or not?
Tooth counts -- diet and head size & shape.
Tooth shapes -- diet.


And the whole list makes up less than 10 characters anyway.

----- Original Message -----
From: "David Peters" <davidpeters@att.net>
Sent: Friday, June 20, 2008 8:17 PM

> If necessary, I can provide references tomorrow. (As I will for
> the claims on LINE insertion... if I don't forget again...)

Sorry. Didn't have time. Had bureaucracy work to do.

So Nandinia isn't the African Palm Civet?

"African", yes. "Palm", yes. "Civet", no -- not for over 10 years now. _Never_ be content with reading Google snippet previews. Actually click the links to the results and read them! And never trust websites that don't look scientific on the phylogeny of anything. Even large parts of Wikipedia are way out of date.


You seem to have missed all of the recent research on carnivoran (crown-group) and carnivoromorph (total group) phylogeny. Several of those papers were in Nature and Systematic Biology, in other words, rather hard to miss.

----- Original Message -----
From: "David Peters" <davidpeters@att.net>
Sent: Friday, June 20, 2008 8:43 PM

Granted, certain tetrapods only need hind feet to climb (woodpeckers, etc.), but mammals, especially Paleocene ones, would have a tough time doing the same. So the question is, if bats were climbing using all fours, why and how would the change to using only the thumbs and folding the other fingers under actually work? IMHO there has to be an intermediate stage because if something is working right (climbing hands) they donât change without intervention.

I repeat: *Onychonycteris*. There we have the intermediate stage. If you still haven't read that paper, I'll send it...


If you look at Ptilocercus and Nandinia, both are quadrupedal climbers, but both hold their prey with their hands. Both enjoy inverted locomotion. Nandinia likes to jump out of trees. Ptilocercus has a fairly naked tail. Not much, but itâs a start.

What next? Whales and mesonychians as sister-groups because of a couple of intercorrelated tooth characters? The "flying primate hypothesis" (flying foxes and only flying foxes as primates -- either two separate origins of flight within placentals, or secondary flightlessness among primates) was much better supported, and yet it is still not the most parsimonious hypothesis, by far.