Re: Social evolution of hominids

Susan S. Chin (
Thu, 9 Jan 1997 06:38:06 GMT wrote:

: I am nobody to disagree with an anthro prof, but I feel uncomfortable
: with this theory. In which way would continuous receptivity (or
: anything else) make the male stay with the female better than a
: chimp male stays with a female in their permanent group? What would
: be the difference in child care if the males and females of a chimp
: group were permanently paired instead of having the way they do?

I see no problem with disagreeing with Lovejoy's theory...many people in
Anthropology have a hard time with it. His theory goes way beyond the
loss of estrus in human females, the subsequent pair bonding as a result,
explained by the advantage for hominid females to have one male providing
for their offspring, this provisioning behavior...eventually led to
bipedalism, as it required that the males free up the hands for carrying
these provisions to the offspring.

There are alot of assumptions here... The advantage for the
males to stay with the one female...presumably is that monogamy ensures
the male that the offspring he is provisioning for are his own, thus
propagating his genes into the next generation....the evolutionary game
goes on, etc.

As for polygamy occurring in modern human cultures... I don't have the
information on this, but one would expect more polygamous bonds with one
male and multiple females...which is consistent with the one egg/millions
of sperm ratio we're working with. Typically in such an arrangement, the
one male is able to provide for all the females and their offspring. The
fact that polygamy exists in various human cultures today is consistent
with adaptive behavioral responses of the hominid lineage to a variable

Comparing orangs, gorillas, chimps and bonobos isn't particularly useful
since we have very little evidence of social behaviors of protohominids
and the common ancestor of humans and apes. The way human ancestors
differed from our closest living primate relatives, is in the expansion
of our habitat beyond a forrested environment. This is one significant
evolutionary change in behavior which likely had direct consequences on
how our ancestors adapted...both morphologically and behaviorally.

: The whole pair system of humans seems to me new and learned.

The degree of sexual dimorphism between a human male and a human female
would at least suggest that differences in size between the sexes nowhere
near approaches that of modern apes such as the orang and gorilla. What
would this suggest to you?

: I find it difficult to imagine, how the mere hanging around of a
: certain man would specially enhance the care of the children. Since
: the number of men and women is equal, there would always be a man
: hanging around, anyway. And since other women are receptive, too,
: continuous sex would be available for him anywhere.

Continuous sex *may* be available to the male, but the long term
viability of his offspring (if they are even his) decreases if this
protohominid doesn't stick around to do some provisioning. It's not
enough to reproduce as much as possible, that's a different strategy
which primates in general have gone away from (#'s vs heavy investment in
a few offspring)

There was never a claim in Lovejoy's Theory that humans have evolved to
accept monogamy as a rule, since that has obviously not happened. Our
social evolution has gone way way way beyond mere providing for our
offspring by securing that next meal (it is hoped anyway)...but when the
basics of life, death and food which your offspring needs... go figure
what the response would be.

: <.snipped>.. instead of luring the man with *more* sex. This, in
: turn, could enhance the care of the children. I believe, that the
: continuous receptivity of women had nothing to do with pairing. In
: fact, the latter could be a step back to restricted mating times.
: Any observations? ;)

Well, not being male, I can't comment on the disadvantage of more
sex...but perhaps your understanding of "continuous sexual activity" is a
bit more literal than its intended meaning. By not having obvious periods
of fertility (estrus) as do other living primates... the human female's
mating behavior is not restricted to that particular time when sex occurs
for the sole purpose of conception. Granted..there's alot more social and
psychological effects to account for as well, once sex was not restricted
to a specific time...hmmm...maybe that's when this pre-occupation with it
all started (jk).