OUR ancestors may have formed monogamous pairs much longer ago than we thought.
The difference in body size between male and female primates is a good guide to their mating strategy. Polygamous males, such as gorillas, tend to be much larger than the females they compete for. Monogamous species tend to be of similar size.
Owen Lovejoy of Kent State University in Ohio and his team compared the sizes of skeletons of Australopithecus afarensis, our hominid ancestor who lived 3.5 million years ago in Afar, Ethiopia, with those of living apes and humans. Differences in body size between male and…
