Path: utzoo!mnetor!uunet!husc6!mailrus!ames!sunybcs!bingvaxu!vu0112
From: vu0112@bingvaxu.cc.binghamton.edu (Cliff Joslyn)
Newsgroups: sci.bio
Subject: Re: Sexual selection
Message-ID: <1022@bingvaxu.cc.binghamton.edu>
Date: 31 Mar 88 03:36:00 GMT
References: <1566@mmm.UUCP> <3138@arthur.cs.purdue.edu> <1164@microsoft.UUCP> <2534@saturn.ucsc.edu> <2701@calmasd.GE.COM>
Reply-To: vu0112@bingvaxu.cc.binghamton.edu (Cliff Joslyn)
Organization: SUNY Binghamton, NY
Lines: 21

In article <2701@calmasd.GE.COM> jnp@calmasd.GE.COM (John Pantone) writes:
>> Sex ratios at birth are ALWAYS nearly even, at least for mammals.
>> This is a biological "fact". 
>
>There  are a
>statistically significant  number of "excess" males born  - by the age
>of  reproduction the ratio   has evened out  -  males  have  a  higher
>mortality.

I was told in high school biology that this trend is actually pre-natal:
that is, significantly more males are conceived and spontaneously abort. 
There are slightly more baby boys than girls, and of course by the time
we're looking at the geriatric populations women far outnumber men. 

Is this true cross-species?

O---------------------------------------------------------------------->
| Cliff Joslyn, Professional Cybernetician 
| Systems Science Department, SUNY Binghamton, New York
| vu0112@bingvaxu.cc.binghamton.edu
V All the world is biscuit shaped. . .