Re: Social evolution of hominids

Susan S. Chin (susansf@netcom.com)
Tue, 14 Jan 1997 06:06:46 GMT

: susansf@netcom.com wrote:
: > Evolutionarily speaking, there's not a great incentive for males of
: > the species to mate with only one female for life. That's why
: > monogamy in a very strict sense (one mate for life, as in the
: > gibbons) rarely happens in humans. The reasoning behind this is
: > fairly obvious for the male, try to spread those genes around as far
: > and for as long as he can. Monogamy does make more sense for the
: > female, since her reproductive resources, unlike that of the male,
: > is fixed. Promiscuity would not produce more offspring, just confusion.

ailak@walrus.megabaud.fi wrote:
: Let's make a rapid analyse of this! These men mate with several
: women, their genes spread in the population, and in due time, most
: men are promiscuous and mate with several women. For the women,
: monogamy is an evolutionary more sensible solution. This means that
: in due time, most women will be monogamous and mate with only one man.
: Evolutionary speaking, it somehow does not work... :)

The basic strategy of one male/one female despite what you care to call
it, seems rather prevalent today. It may not be "natural" but it is what
does work in many societies... imperfectly at times. There is nothing to
suggest that early hominids could not have adopted such a reproductive
strategy.

: What if both men and women were promiscuous, to a certain extent, as a
: remnant from a long, long promiscuous period in the prehistory of our
: species. We are only learning, how to be monogamous?

What is your basis for this recent acquisition of monogamous behavior?

: >I don't know that this behavior pattern in human females could be termed
: >"fixed" genetically, aside from the fact that XX sex chromosome tends to
: >result in less promiscuous sexual behavior. Professor Vince Sarich used
: >the following example in his evolution of human behavior class, namely
: >"How many male prostitutes are out there, compared to female prostitutes?"

: This behavior pattern in human females *can not* be termed as fixed.
: If it was, no woman, ever, could have sex but with one man in her
: life, as far as he lived. This is how it is with the gibbons?

Your interpretation of monogamy is much more literal and restrictive.
Human monogamy in no way approaches that of the gibbons... I don't think
anyone would argue with that. Monogamy when applied to humans should
refer only to "serial monogamy" one mate at a time...that works both
evolutionarily and is what we observe today in many human societies.

I would also hesitate to call any human behavior as "fixed" at any level
of genetics. What I said earlier, that the XX chromosome and correlation
to less promiscuous sexual behavior, is an empirical observation. There
are always the exceptions, it therefore isn't "fixed" but rather the
behavior does seemingly have a high correlation to individuals with the
XX chromosome.

: Prostitution in our society has historical grounds, and average women
: never could afford a prostitute, even if they would have wanted.
: Where women had power, like queens and the top class, they used any
: man who pleased them in their vicinity. It has also been stated, that
: XX results in less sexual desire... Depriving the cultural context, I
: don't think his argument holds.

Why don't you think the argument holds? Just because something is
culturally based and influences our behavior, does not mean that this
behavior doesn't also have a genetic or biological component to it.

Another example Sarich used was the comparison of mating behavior of
homosexuals, of gay men and lesbian relationships. Promiscuous sexual
activity (esp. pre-AIDS period) predominated in male homosexual
relationships. Monogamy on the whole largely predominated in lesbian
relationships. What does this suggest?

: >The whole concept behind Lovejoy's theory is that since sex and
: >the *possibility* of conception, therefore offspring, is continuous,
: >year round, throughout the entire month, pair bonds become a better
: >reproductive strategy out in the "savanna"...
: snip

: It is the length of
: pregnancy and lactating, not the interval of ovulations, which
: determines the birth rate.

Another consequence of pair bonding is that, with the help of the male
parent in providing for the care of his offspring, this enabled the
hominid female's reproductive cycle to become spaced closer
together... This is important since mortality rates during this
time... could not compare to infant mortality rates today in societies
with modern medicine and conveniences. The best strategy would therefore
be producing as many offspring as viably supportable...with the
expectation that infant mortality may be a rather frequent occurrence.

Susan

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                                             susansf@netcom.com