Newsgroups: sci.bio
Path: utzoo!rising
From: rising@utzoo.uucp (Jim Rising)
Subject: male lactation
Message-ID: <1988Feb25.144629.3650@utzoo.uucp>
Organization: U of Toronto Zoology
Date: Thu, 25 Feb 88 14:46:29 GMT

I know nothing about the physiology of lactation in mammals, but confess
that I suspect that there is some fundamental reason why it "won't
work" as a general strategy.

I say this because it is unknown in the Mammalia (with the possible 
occasional--and probably pathological--excption of humans).  In many
kinds of animals where it is possible for the males to care for and
feed the newborn young it is common that the male plays an important--and
often exclusive role in these activities.  I can think of many fish,
birds, amphibians, and insects off the top of my head.  Presumably these
systems evolve in situations where such activity increases the fitness
of one and probably both of the parents, and where it is possible for the
male to raise the young.  Probably most commonly this is because it frees
the female to produce a second (etc.) brood, doubling the ante for her
(and probably both).

The fact that this sort of system doesn't occur in the Mammalia suggests
to me that it is not possible because (for physiological reasons) the 
males cannot suckle the young.   Roy Smith may be right when he says
that it would prevent the males from conceiving.  I suspect that the con-
ditions leading to male lactation may be cause by hormal imbalances of
sufficient magnitude to reduce fertility. [should read: "caused by hormonal"
above]

--Jim Rising
-- 
Name:   Jim Rising
Mail:   Dept. Zoology, Univ. Toronto
        Toronto, Ontario, Canada    M5S 1A1
UUCP:   {allegra,ihnp4,linus,decvax}!utzoo!rising