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Re: parental care (was Re: RE: Dinosaur Planet, parts 3 & 4 )



On 12/20/03 11:53 PM, "ANN SCHMIDT" <ashmidt@flash.net> wrote:

> --- Ken Carpenter <Kcarpenter@dmns.org> wrote:
>> Here is the problem, just because SOME extant
>> vertebrates care for their your is not PROOF that
>> dinosaurs did. It is INFERRED that they did because
>> some do today. That is the big difference. An
>> inference may be very logical but is difficult to
>> frame as a testable hypothesis.
> Yet can't it be admitted that not caring for their
> young would be highly unusual given how widespread it
> is among so many animal groups today?  Land
> vertebrates in geenral seem to, not just "some" of
> them either.  Except for a very few specialized
> species (that still devote a ton of energy to to
> enable them to not care for their young), all modern
> birds from every group care for their young, all
> modern mammals do, all modern crocodilians do (some
> more than others) whiel many modern amphibians,
> lizards and even snakes do.

Parental care doesn't seem that widespread to me.  Most birds do care for
their young, granted, but parental care is probably ancestral for modern
avians.  Same goes for mammals, and their constrained by nursing anyway.

Of the 4000+ amphibians, only a few show any real parental care, and of the
ca 300 turtles and nearly 7,600 species of squamates, only ONE is documented
to show true parental care (the king cobra, Ophiophagus hannah).  A few
others are suspected, but not really shown conclusively to do so.

It seems like "lay 'em and leave 'em" is actually very common.  Parental
care makes a strong mark today because most of the 10,000 birds on the
planet use it.  Even then, probably close to half of the worlds terrestrial
vertebrates do not show any parental care.

--Mike Habib