So, what about the other condition?

What strategy might females have devised

to punish uncooperative males? One

suggestion is that women formed strong

coalitions that wielded their power by

withholding sex. A successful coalition

would have required them to

communicate and coordinate their action

and send out strong signals to the men,

telling them they were fertile but

temporarily unavailable. It's a tricky

signal to communicate, because signs of

fertility would have been a big attraction

for the males, yet at the same time the

females had to persuade them to go off

hunting. They’d have to plan, be devious,

and know what the others were doing-all

of which would have constituted a form of

culture. And that's were the red ochre

comes in.

The theory is based on an idea proposed

a decade ago by Chris Knight from the

University of East London and developed

by Camilla Power of University College

London. They point out that features of

the modern human female reproductive

cycle, such as concealed ovulation and

continuous sexual receptivity, could have

evolved as ways of encouraging males to

stick around. But these signals alone

wouldn't prevent the strongest males from

monopolising females-by noticing

menstruation they could systematically

identify and target females as they

approached the peak of fertility. This

would have became a problem as females

became increasingly reliant on help to

meet the costs of reproduction.

Knight suggested that our female

ancestors synchronised their reproductive

cycles so that a dominant male simply

wouldn't have time to service all the fertile

It was Power who realised that women

needn't synchronise their cycles to benefit

from menstrual coalitions, they just had to

fake the signs. She believes that around

500,000 years ago, when brain size started

expanding rapidly, menstruating women

would have become a threat to other

females by attracting much-needed male

attention. So women who were nursing

and pregnant took control of the situation

by feigning menstruation. At first, this

"sham menstruation" was improvised and

impromptu, perhaps with women

borrowing one another's blood or using

animal blood. "Then everything becomes

symbolically organised rather than ad

hoc," she says, "and that would have

triggered the regular use of red ochre."

The emergence of "sex strikes" is more

difficult to explain. Menstruation is a

woman's best advertisement of fertility so,

contrary to what most people think today,

it is a huge come-on. The problem for

female coalitions would have been that

rather than attracting their men, they

needed to persuade them to leave the

camp to hunt. Our ancestors would have

had to devise a very powerful cultural

"no" signal to counteract the strong

biological "yes" that menstruation gives

out.

"To say ‘no’ in the loudest possible way,

you don't use words, you do things that are

the exact opposite of what you would do if

you were going to make ‘yes’ signals,"

says Power. "To say ‘no’, you do the

reverse of being a human female-you

pretend to be male and you pretend to be

an animal."

Combining a come-on with a turn-off

may seem a little far-fetched and, of

course, there's no turning the clock back

150,000 years to see how our female

ancestors behaved. But Power has done

the next best thing: she has been

studying initiation rituals in sub-

Saharan traditional societies, in which

such strategies may persist to this day.

Part of a girl's puberty ritual among

the Khoisan, for example, is a dance

called the Eland Bull Dance where the

girl plays the part of the bull, sending

out a "wrong sex, wrong species"

signal. Meanwhile, the women of the

camp dance around her as if mating with

the bull, taunting the local men with

their complete lack of interest in them.

"The message to the males is absolutely

clear-you go off, you hunt some eland,

and then we'll see. It's a sex strike in all

but name," says Power. The Hadza have

a similar ritual called "epeme", linked to

symbolic menstruation and the new

moon, associated with a mythical

heroine who hunts down male zebra and

wears their penises.

In a recently completed study, Power

found that in a range of traditional

societies puberty rituals link menstrual

taboos with hunting, lunar phase and

"wrong sex" signals in ways that meet

the predictions of the sham

menstruation and sex strike theory. "It’s

wildly improbable that any of that is

going to be there by accident," she says.

And there is more evidence in the

archaeological record, says Watts. His

study of 74 sites in southern Africa

dating from more than 20,000 years ago

reveals an explosion in the use of red

ochre and other red pigments between

about 100,000 and 120,000 years ago.

And, he says, new findings in Zambia

and the re-dating of the important

Border Cave site in South Africa push

the date of the earliest use back further

still-perhaps to 170,000 years ago in

Zambia.

Some have yet to be convinced about

the symbolic purpose of ochre,

especially so early in our history,

believing that it might instead have been

used to preserve hides. But Watts

doesn’t buy this. He admits that iron

oxides neutralise collagenase, an

enzyme used by bacteria to break down

fibrous collagen, but studies of Kalahari

bushmen suggest hides wear out before

they succumb to bacterial decay. And

Watts's own research reveals that our

ancestors went out of their way to

collect high-quality red iron oxides,

even when other oxides of different

colours were available locally and could

have preserved hides just as well. Red

ochre has got to be culturally

significant, argues Power. "Suddenly

people just want to body-paint. Well,

why?" she asks. "This is the only

Darwinian explanation for why on earth

that ochre is there."

Of course, not everyone is convinced,

but anthropologists are starting to take

the idea seriously. One of its strengths is

that it addresses the question of why

symbolic culture evolved, rather than

simply how it did so, according to

Robin Dunbar from the University of

Liverpool. He agrees that the dynamics

of social groups must have been an

important factor.

"Knight's story is a powerful one

because it makes a number of very

specific claims", says Robert Aunger

from Cambridge University. Even so, he

has yet to be convinced by the evidence.

"It is just one story among many in an

area still so ripe with controversy that it

will take history a long time to sort out

who's right and who's wrong."

Is it frivolous to suggest that

cosmetics are the roots of human

culture? Power's answer is an emphatic

no. She points out that the word

"cosmetics" comes from the Greek,

"cosmos", meaning order. "In

traditional cultures cosmetics are not

mere frippery," she says. They define

who belongs to which group, who can

touch who, and who can mate with who.

"The regularised use of cosmetics as a

sexual signal could even have been the

thing that marked off modern humans."

So perhaps lipstick is not just the key to

culture, but also to the origin of our

species.

13 October 2001 • New Scientist • www.newscientist.com