soft spots
alex duncan (aduncan@mail.utexas.edu)
14 Aug 1995 21:44:03 GMT
In article <40fhjs$lqd@portal.gmu.edu> HARRY R. ERWIN,
herwin@osf1.gmu.edu writes:
>: >This is why the head of the human infant is
>: >"soft" and contains a partial "soft spot" in the skull so that it is
>: >better able to slip down the birth cannal.
>
>: I'm a little baffled. If this is WHY human infants have unfused cranial
>: bones (resulting in "softness"), why do the same features show up in all
>: other mammals, and even birds? Do birds need a "soft" skull to get out
>: of their eggs? I would think a hard skull would help them break out of
>: the shell better.
>
>: (That was sarcasm, above. I'd hate to think no one noticed.)
>
>: There's just got to be an adaptive explanation for EVERYTHING.
>
>Unfused sutures allow the brain to grow.
Give me some credit, Harry. I'm aware that unfused sutures allow the
brain to grow (an adaptation). I was satirizing the suggestion that we
have unfused sutures to allow us to squeeze down the birth canal (an
exaptation).
Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086
512-471-4206
aduncan@mail.utexas.edu
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