The social structure of human ancestors could be like gorillas
Exploring the sagittal crest of the four species of monkeys, scientists have found indication of its relationship to social hierarchy. The authors concluded that this bone formation on the top of the skull grow not only as an evolutionary advantage for the attachment of masticatory muscles, but also due to sexual selection. Article anthropologists published in the Journal of Anatomy.
“We found that in the case of males gorillas and orangutans not only chewing stimulates the formation of comb — says Catherine Balolia from the Australian national University, lead author of the study. — This is also a social element: for example, females prefer males gorillas with large sagittal crests”. The authors say that this discovery may indicate the social interaction of the extinct relatives of humans, as some of them possessed such formations in the skull.
“We might be able to establish that some of our extinct relatives had a social system similar to an existing gorillas have, adds Dr. Balolia. — This would be the first information about their social behavior, since fossils almost nothing allow you to learn about how they chose their partners.”
The researchers studied three-dimensional scans of skulls and found two prove their hypothesis. “Gorilla males establish social dominance soon after the emergence of wisdom teeth, adds the author. We found that the sagittal crest appears at the same time, that is, coincides with the time of the establishment of dominance. The orangutans some males can become dominant enough later, already as adults, and a sagittal crest which also appears later.” In addition, statistical modeling shows that the ridge in these species is greater than would be expected on the assumption that additional space for the attachment of chewing muscles — its only function.