Re: Social evolution of hominids

Susan S. Chin (susansf@netcom.com)
Sun, 12 Jan 1997 08:11:34 GMT

: debra.mckay@utoronto.ca wrote:
: > I'm a little uncomfortable with your comments on the !kung san and
: > sub-Saharan Africa in general. The !kung, we should keep in mind,
: > are *not* a representative of the behaviour or anything else of early
: > humankind; they are a group of modern people. We must be *extremely*
: > careful with our use of analogy.

ailak@walrus.megabaud.fi wrote:
: Just because they *are* modern people, I think they may be
: representative. Do you think, that if children from any other
: people were raised in a !kung san society, they would seek
: permanent or longer pair bonds than their step mothers? What I
: see around, makes me think that !kung san differ mainly in having
: retained an old-fashioned *culture*.

: I'm not so much seeking an analogy, but trying to show, that the
: 'monogamy' which most cultures try to support, is not yet a basic
: behaviour of modern man. It has been the most succesful strategy
: for a length of time, and if practised long enough, will select
: for personal traits which fix the behaviour at genetic level, too.
: This has not really happened, so this strategy can't be old, in
: the paleontological sense, I mean.

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.

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?"

Again paleontologically, the decrease in sexual dimorphism represented in
the hominid lineage does suggest that changes occurred due to changes in social
behavior of hominids through time. And changes such as these rarely occur
in a very short amount of time as was suggested.

: > As to sub Saharan Africa, my husband
: > in-laws would probably dispute your characterization of "free sex": wh
: > I agree that polygamy is probably the normal condition of the human ma
: > system, sex in those cultures is probably less "free" than we Westerne
: > characterize ourselves. A woman with more than one husband is polyand
: > Rare, but known.

: Just what I have read about AIDS spreading in African populations.

I've read that it has more to do with a reluctance to use the proper
protective contraceptives, which doesn't necessarily imply promiscuity,
though it could. That, or the lack of said contraceptives in many parts
of Africa.

: > Yeah, but if he doesn't think the kid is his, what would motivate
: > him to help look after it? If he thinks it *might* be his, he
: > may be more inclined to stick around.

: Yes of course, and the more he invests in children in general, the
: more interest he should show in their descent. What I opposed (and
: not very succesfully indeed) was that continuous sex *alone* would
: have initiated pair bonding in a group of hominids. Life long
: monogamy may appear where sex is once a year, and promiscuity, where
: sex is continuous, so these two do not follow directly from each
: other.

Sex once a year... very doubtful any primate species would survive such a
reproductive cycle... non-conception, miscarriages, non-viable
offspring... when this occurs, the next reproductive opportunity is quite a
few long months away. Now why on earth (or anywhere else) would a male
stay around for this type of reproductive behavior? 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"... there was likely competition among the males as
previously, but perhaps this hypothesized cooperation between the sexes
in rearing offspring was the difference. There are more unlikely
scenarios which seek to explain the same phenomena of our uprightness.

Susan 

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                                             susansf@netcom.com