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Re: origin of bats/suspect trees?



David Peters (davidpeters@att.net) wrote:

<You just shot yourself in the foot. Few to no molecular results replicate 
morphology. And I did say "using morphology">

  Very well. Ignore molecules, which seems easy I guess if you can find 
detailed comparative anatomy for every odd, wierd or bizarre mammal one can 
possibly fit into their analysis. Some don't exist, but this should be fine.

  As for replicating morphology, this is actually not true. There are enough 
genes who relevant to a morphological suite are known, such as sonic hedgehog, 
which is perfectly capable of being mapped onto a morphological tree to 
consider its effect. You can constrain one morph data set to agree with a mol 
one, and map a character or gene appearance and determine compatability. Not 
that this is hard.

<Blood work is not definitive. Morphology rules.>

  I cannot see how this deserves much, if any comment, other than that 
morphology more often than not a product of genes, not the other way around.

<Martin and Feduccia have just entered the room. The single character mindset. 
Where's the suite Jaime?>

  While David is correct in averring that manatees has rounded, oblate ribs, my 
argument arose through comparative suites of features. There were comments 
which were brought up about correlative features, such as elongated 
forelimbs/elongated hindlimbs, elongated metatarsals and an elongated calcaneal 
heel. Lower down I mention teeth, and this is even more securely true, and I 
even mentioned sloths as an example of this, despite their differences.

  Moreover, different animals in similar habitats have similar physiologies, 
indicating that we can take a feature or suite of features and note that these 
are related to that behavior; there are features tied to fossoriality, 
arboreality, cursoriality, perching, brachiating, suspensoriality, opposability 
of the hallux/pollex, etc.

<I said pedal, remember?>

  Irrelevant. You don't think a constraint in habitat like suspension would 
promote elongation of the phalangeal proportions, as it does in brachiating 
apes? If not, then there should be even less reason why animals that do not use 
the fingers for propuslion should ever have such digital proportions. Bats do 
not possess the pedal proportions of brachiators, meaning that walking around 
on their feet upside down is not a behavior they engage in in any regular 
past-time. They do not, they lack such proportions, and thus one might expect 
they lack such constraints any so-called "terrestrial bipeds" possess.

<and yet, there are patterns and suites of patterns. You've got to think about 
the whole critter.>

  Which is why I mentioned diet. Look at predators: dental anatomy must be 
suited to rendering prey, the animal must be capable of processing 
proteinaceous material, and the animal must have the energetic regime to 
acquire the prey in the fIrst place. Finding a ziphodont crown can tell us that 
the animal is suited to cutting flesh. If that crown had denticulations, we 
would expect the prey item to possess possible muscular tissue, and likely be 
vertebrate in nature. Possession of a jaw full of ziphodont teeth tell you the 
animal is a strict carnivore. If the dentition is heterodont, with molariform 
or incisiform teeth, then we can expect the diet to vary, and can expect there 
to be more generalistic features of the body. This is what you can expect from 
a single tooth. And that's just the apex of the crown.

  Different animals with different evolutionary histories will convergently 
acquire the same dental features given the same dietary avenues.

  Cheers,

  Jaime A. Headden