Xref: utzoo sci.bio:1016 soc.men:3102
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From: g-rh@cca.CCA.COM (Richard Harter)
Newsgroups: sci.bio,soc.men
Subject: Re: sexual selection and investment
Message-ID: <25934@cca.CCA.COM>
Date: 24 Mar 88 05:22:13 GMT
References: <1988Mar13.160941.22096@utzoo.uucp> <25527@cca.CCA.COM> <2403@saturn.ucsc.edu> <25669@cca.CCA.COM> <1125@3comvax.3Com.Com>
Reply-To: g-rh@CCA.CCA.COM.UUCP (Richard Harter)
Organization: Computer Corp. of America, Cambridge, MA
Lines: 36

In article <1125@3comvax.3Com.Com> michaelm@3comvax.UUCP (Michael McNeil) writes:

>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.  

If you take all species of animals for your standard of comparison,
then the norm is for the female to be substantially larger than the
male.  If you take all species of vertebrates for you standard of
comparison, then I suspect that you will find that males are larger
than females, on average, but not to the extent characteristic of
humans.  If you take large mammals (and humans are large mammals)
as your standard of comparison, then I think you will find that 
find that humans are less dimorphic.

Re the loss of dimorphism during our evolution.  It is my impression
it was about the same as that of modern day humans for Afarensis,
H. habilis, H. erectus, and H. Neanderthalis, and the Boseii was more
dimorphic than humans.  If any one out there knows for sure, I would
be interested in hearing about it.
-- 

In the fields of Hell where the grass grows high
Are the graves of dreams allowed to die.
	Richard Harter, SMDS  Inc.