From: Mike Lorrey (mlorrey@yahoo.com)
Date: Tue Nov 05 2002 - 15:21:14 MST
--- Anders Sandberg <asa@nada.kth.se> wrote:
> On Tue, Nov 05, 2002 at 12:26:44AM -0800, Zero Powers wrote:
> > >From: spike66 <spike66@attbi.com>
> >
> > >Question please, evolution wonks: since most
> > >mammals have multiple offspring and consequently
> > >have 4 pairs of nipples, are humans ever born with
> > >vestigial extra pairs of nipples?
> >
> > A similar question I've wondered about from time to time is: Why
> do *men*
> > have nipples?
>
> Because the default is to be a female. The fetus starts to
> develop into a male as various regulatory genes are activated
> by hormones. The development of nipples and milk ridges start
> (in week three or four) before these genes really come online
> (in week seven), so the nipples are vestigial in males. They
> seldom cause trouble, so there is no evolutionary pressure to
> get rid of them.
I actually think that they serve an evolutionary function. They are
simple weather instruments, telling the owner a) "It's time to get out
of this freaking COLD water or we're gonna die, you moron!", or b) "Its
time to skin an animal and wear some fur, you dumb naked ape!".
__________________________________________________
Do you Yahoo!?
HotJobs - Search new jobs daily now
http://hotjobs.yahoo.com/
This archive was generated by hypermail 2.1.5 : Wed Jan 15 2003 - 17:57:58 MST