The full, plump breasts seen in the human ape is an anomaly.
No other primate has a permanent breast. During lactation all
the ape species develop a full breast to store milk.
In non-human primates (and other mammal species) a full breast
is a clear indication the female is suckling young. Not so in humans.
Full breasts aren’t a reliable indicator of fertility.
Neither is size an indicator of milk production.
Bigger breasts don’t necessarily produce more milk.
It’s the symmetry of the breasts which
indicates the phenotypical quality and fitness
of the individual female, not the size.
Breasts help females attract mates.
Like the ostentatious feathers of
male peacocks, breasts serve as a
message to the opposite sex.
“Hey, look at these! Reproduce with me!”
Those fat mounds are a signal
of a woman’s mate-worthiness.
Paleolithic cave art dating back 35,000 years
portrays naked women with enormous hips and breasts.
Perhaps that’s pre-historic porn, or maybe
it has to do with reproductive fitness.
Just as any size penis can cause a pregnancy,
all breasts can swell with milk and nurture infants.
But evolution seems to have primed men
to believe that women with larger breasts
are a better reproductive bet.
Long before the contemporary obesity epidemic,
when food was scarce and starvation a real threat,
large, fatty breasts suggested caloric reserves.
That, in turn, suggested that the women had
reliable access to food, which increased
survival odds for their offspring and their impregnators.
The sex appeal of rounded female buttocks and plump breasts
is both universal and unique to the human primate.
Fertile women tend not to store fat around the abdomen,
so the waist of a fertile female is usually slimmer than her hips.
Other female primates do not have fat deposited on the rump.
For example, the female gorilla has a skinny posterior and
stores fat on her abdomen, as do human males.
It has been widely theorised that the plump buttocks and breasts
of modern women are sexual ornaments, selected for by ancestral males.
