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From: crovella@sunybcs.uucp (Mark Crovella)
Newsgroups: sci.bio,soc.men,soc.women,sci.misc
Subject: Re: Rape a reproductive advantage?
Message-ID: <7760@sunybcs.UUCP>
Date: 11 Jan 88 14:21:13 GMT
References: <517@gtx.com>
Sender: nobody@sunybcs.UUCP
Reply-To: crovella@gort.UUCP (Mark Crovella)
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Organization: SUNY/Buffalo Computer Science
Lines: 56

In article <517@gtx.com> scm@gtx.UUCP (Sue Miller) writes:
>
>>
>>>>>I expect there's an evolutionary advantage.  Rapists probably reproduce
>>>>>better than non-rapists.
>>>>>
>>>>>Keith Doyle
>>>>
>   Not really.  Not unless you intend "non-rapists" to mean ONLY those
>individuals who otherwise have no other way to pass on their DNA.
>Otherwise, if it were an advantage that increased one's fitness (a la
>Darwin, not Jack LaLanne ;-) ) I would certainly expect it to be exhibited
>more frequently.

I believe that behavior such as this is fairly common among
species that do not develop lasting pair bonds.  If one parent
has no requirement to invest energy in the offspring (in the form of
feeding, nurturing), it is to that parent's advantage to attempt to
reproduce as often as possible. Since females cannot do this in the
limit, so-called "rape" behavior occurs only in males.

>  As it is, I am not sure that rape as we humans know it
>even exists in any other species - although the example of cricket sexual
>behavior comes close I guess.  

Mallards (_Anas_ sp. -- ahem! :-) exhibit behavior which is termed
by ornithologists as "rape" or "gang rape".  Late in the season, after
young have hatched, males will encircle a lone female and some of them
will copulate with her.  I don't think that these unions generally
lead to successfully fledged young -- it is too close to migration,
the females are really not physiologically prepared to raise another
clutch.  I think there are really quite a few other examples out there
among all that diversity. Note that
non-pair bonding species generally exhibit much greater sexual
dimorphism (colorful males, larger males, etc.) because a new
pair bond is formed every year.  In this case, a distiguishing
feature make help a female "make up her mind" to select a given male, 
and this feature becomes a reproductive advantage.  This makes me
think that the cricket example is an example of a non-pair bonder, also.

>Any social/behavioral biologists out there care to comment? 

Where there is an advantage to a behavior, directly accruing from
differential reproduction (= "fitness"), that behavior will usually
be exhibited.  I'm not a social or behavioral biologist, but I
think this is a central tenet of ethology (behavioral biology).

> -------------------------------------------------------
> |  Sue Miller         UUCP: ihnp4!sun!sunburn!gtx!scm |
> -------------------------------------------------------

Mark Crovella

Mark Crovella
uucp:	  ..!{ames,boulder,decvax,rutgers}!sunybcs!crovella
internet: crovella@cs.buffalo.edu         bitnet: crovella@sunybcs.bitnet