William Flew on Cavemen and Women

Women roamed the landscape while the men in early human tribes stayed close to their birthplace, according to scientists.

The finding, based on fossilised teeth between 1.7 and 2.4 million years old, suggest a “foreign bride” culture prevailed in two ancient hominid species.

The teeth were found at two sites in South Africa and belonged to Australopithecus africanus and Paranthropus robustus, both part of a line of close human relatives that included the Ethiopian fossil “Lucy”.

Our female forebears would have grown up close to their birthplace, but moved to mate with males from other tribes early in adulthood, according to the study. Males, by contrast, strayed only a few miles from their birthplaces at the two sites, the fossilised remains have revealed.

“Here we have the first direct glimpse of the geographic movements of early hominids, and it appears the females preferentially moved away from their residential groups,” said Sandi Copeland, of the University of Colorado Boulder, who led the study.

Intriguingly, the female dispersal pattern seen in the two hominid groups, which were on the brink of becoming human, is similar to that in many modern human societies. “More often, the woman is the one that leaves,” said Dr Copeland. “In China and India, for instance, young women traditionally move to live in the husband’s family home.”

However, she said that it was not clear whether this trend emerged with the advent of agricultural society and the inheritance of land or whether it was rooted deeper in our ancestral past.

The work overturns previous assumptions that early hominids would have travelled for days to forage for varied food supplies, and indicates that they may have relied more heavily on grass and plant roots for nutrition. The study, which is published today in Nature, tested 19 teeth belonging to Australopithecus africanus and Paranthropus robustus from the Sterkfontein and Swartkrans caves in South Africa.

More than half the females grew up outside the local area and moved there as young adults, chemical signatures in the tooth enamel revealed. By contrast, 90 per cent of the males appeared to have lived within a few miles of the caves throughout their lives.

“This study gets us closer to understanding the social structure of ancient hominids since we now have a better idea about the dispersal patterns,” said Dr Copeland.

Why the males preferred to stay close to the cave sites remains unclear. One possibility is that they preferred the vegetation or a landscape dominated by dolomite rock where there would have been an abundance of caves. Another possibility is that close male co-operation and conflict between groups produced strong male loyalty towards their own group.

A. africanus lived between 2 and 3 million years ago and is believed to be directly on the human ancestral line. P. robustus, which lived between 1.2 and 2 million years ago, is likely to have been a side-branch on the human family tree.