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From: barger@ils.nwu.edu (Jorn Barger)
Newsgroups: sci.skeptic,sci.bio
Subject: Re: Further Evolving Eyebrows
Message-ID: <2431@anaxagoras.ils.nwu.edu>
Date: 2 Nov 90 21:23:21 GMT
References: <1371@cluster.cs.su.oz.au>
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Organization: Institute for the Learning Sciences
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In article <1371@cluster.cs.su.oz.au> louie@cluster.cs.su.oz.au (Luis 
Esteban) writes:
> I have received a number of solutions to why we have
> eyebrows.  I have some questions concerning them.
> The following is a composition of the explanations and questions. 
[stuff deleted]

I've been waiting for years for someone to ask me this (why do humans have 
eyebrows).  It seems transparently obvious to me that they are primarily 
_signal-flags_, bars of contrasting color that amplify our emotional 
expressions, making them readable more easily at a greater distance.

Why did humans lose their fur?  This seems surely due to sexual selection, 
not natural selection.  But why this baldness became sexually attractive I 
have no clue. 

In general, sexual selection is not considered often enough as an 
evolutionary force.  I think that the punctuated equilibrium paradox makes 
perfect sense if viewed as a case of sexual selection overpowering natural 
selection until the environmental stresses finally become too great.


................................................................... 
"The man who pretends to be a modest enquirer into the truth of
a self-evident thing is a knave." William Blake
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