Xref: utzoo sci.bio:1015 soc.men:3099
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From: michaelm@vax.3Com.Com (Michael McNeil)
Newsgroups: sci.bio,soc.men
Subject: Re: sexual selection and investment
Message-ID: <1125@3comvax.3Com.Com>
Date: 23 Mar 88 16:19:18 GMT
References: <1988Mar13.160941.22096@utzoo.uucp> <25527@cca.CCA.COM> <2403@saturn.ucsc.edu> <25669@cca.CCA.COM>
Reply-To: michaelm@3comvax.UUCP (Michael McNeil)
Organization: 3Com Corp., Santa Clara, CA
Lines: 47

In article <25669@cca.CCA.COM> g-rh@CCA.CCA.COM.UUCP (Richard Harter) writes:
>In article <2403@saturn.ucsc.edu> kevin@chromo.UUCP (Susan Nordmark) writes:
>
>	... Re my comment that humans are markedly dimorphic
>
>>Actually, humans are only moderately dimorphic. Examples of species
>>with a strong degree of dimorphism are gorillas and baboons--in 
>>these species males may be up to twice as massive as females.
>>This doesn't happen among humans (of course what's scientifically
>>relevant here is the degree of dimorphism within the sort of genetically 
>>homogenous, small interbreeding populations that were the venue
>>for evolution.
>
>Terms like markedly and moderately depend very much on which apples
>and oranges you are comparing.  If your context is the great apes,
>humans are moderate.  If you context is mammals in general, humans
>are well up there.  If your context is pair-bonding mammals with
>paternal sharing in the support of the young, humans are highly
>dimorphic.  And if your context is anglerfish, the dimorphism is
>marginal [Natural science joke -- if you don't know, don't ask.]

To quote Jacob Bronowski in this regard:

	[...] in general there is much less difference between men
	and women (in the biological sense and in sexual behavior)
	than there is in other species.  That may seem a strange
	thing to say.  But to the gorilla and chimpanzee, where
	there are enormous differences between male and female,
	it would be obvious.  In the language of biology,
	dimorphism is small in the human species.
		Jacob Bronowski, *The Ascent of Man*, 1973

I might also add that since our closest living relatives are the
gorillas and chimpanzees, which are much more markedly dimorphic,
humans most probably lost much dimorphism during our evolution.  

Michael McNeil
3Com Corporation
Santa Clara, California
	{hplabs|fortune|idi|ihnp4|tolerant|allegra|glacier|olhqma}
	!oliveb!3comvax!michaelm

	William James used to preach the "will to believe."  For
	my part, I should wish to preach the "will to doubt." ... 
	What is wanted is not the will to believe, but the will
	to find out, which is the exact opposite.  
		Bertrand Russell, *Sceptical Essays*, 1928