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Re: Lamarckian



--Original Message-- From: Philidor11@aol.com Date: 11 November 1998 20:05



>In a message dated 11/11/98 2:07:45 PM Eastern Standard Time,
>th81@umail.umd.edu writes:
>
><< Among the ancestors of the maniraptorans, there existed some variants in
>the
> population with arms somewhat longer than their kin.  These elongated
limbs
> favored their bearers, as they had a wider grasping area than other
members
> of their population.  With a greater success rate at killing, they had a
> better than average chance of surviving to adulthood, and passing on this
>trait. >>
>
>I was hoping that the rephrasing might also include references to pack
hunting
>and other behaviors such as the choice of prey and the manner used to
attack
>them.
>I notice the number of different social activities mentioned such as
herding,
>migration, and nursery areas, and it seemed that a number of animals were
>transmitting behaviors learned in life along with related physical
>characteristics through the generations.
>Speaking of behaviors, I'm still wondering how a crocodile (alligator?)
first
>'thought' of picking up offspring in her mouth and carrying them to a safer
>location.  Even more, how on earth she 'taught' the other crocs.  I know
>teaching is a difficult profession, I've tried to introduce new forms to
>correctional officers, but that has to be some kind of record.



When did the first croc NOT eat its prey, but picked it up etc?  Always
interesting to try to imagine such a sequence!  Sometimes of course, the
original or intermediate behaviour is practically impossible to guess from
the final stage.  However, A possible sequence might be: clearing away nest
debris (carefully); carefully finding young in jaws and not biting; starting
to wander off to the river with young in jaws etc.

However, neither in this, nor in Tom's quote above, is any learning
required.  Learning does however have an interesting evolutionary effect.
It can speed up the evolution of other aspects.  It does of course have
tremendous overheads (you have to unlearn instinct first etc; takes time to
learn).  It's a hard characteristic to evolve.

I wanted to answer your previous post on this but it was too complicated.

JJ