"Walter Murray" <[log in to unmask]> writes:

>  "Wirt Atmar" <[log in to unmask]> wrote:
>  > Humans are as much a quadraped as any other mammal, but are given
>  > special status due to their bipedal gait. The only question in regards to
>  > counting is whether you credit humans with two or four feet.
>
>  So if you call a tail a paw, how many feet are there?

Humans have as much of a tail as do cats, it simply doesn't erupt through the
fleshy part of your bottom any longer.

This kind of slight developmental modification occurs constantly as one body
shape evolves into another. Human hands and feet are constructed in virtually
identical manners, but with the evolution of an arboreal lifestyle for
primates and later the development of a bipedal gait, the hands were freed for other
uses. As a consequence of that morphological change, the fleshy part of the
forepaw retreated back to where you see it now. But if you imagined the flesh
moving back up one knuckle on your hand -- and the first phalanx (finger bone)
of each finger becoming much longer, with your second phalanx becoming shorter,
your hand would become essentially a foot again.

Konrad Lorenz's (Nobel Laureate in animal behavior) major professor was fond
of saying that "bones are like wax in the hands of evolution."

Creationists often decry the idea that we're descended from monkeys, but
we're not. We're descended from fish -- and the tetrapodal design plan of four
limbs and a tail that dictates the structure of all terrestrial vertebrates was
well in place before the first vertebrate crawled out onto land. For a
simplified diagram of that ancient architecture:

     http://aics-research.com/vertschema.html

Wirt Atmar

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