Washington, Nov 3 (ANI): Scientists from universities of Southampton and Calgary have discovered that Neanderthals were much more promiscuous than people today.
The scientists examined finger ratios from fossilised skeletal remains of early apes and extinct hominins to reveal our ancestors' behaviours, particularly aggression and promiscuity.
The finger ratios were used as indicators of the levels of exposure species had to prenatal androgens - a group of hormones that is important in the development of masculine characteristics.
It is thought that androgens, such as testosterone, affect finger length during development in the womb. High levels of the hormones increase the length of the fourth finger in comparison to the second finger, resulting in a low index to ring finger ratio.
Analysis of the finger ratios revealed that Neanderthals they had been exposed to high levels of prenatal androgens so they were likely to be more competitive and promiscuous than people today.
Also, early hominin, Australopithecus, was likely to be monogamous, whereas the earlier Ardipithecus appears to have been highly promiscuous and more similar to living great apes.
"It is believed that prenatal androgens affect the genes responsible for the development of fingers, toes and the reproductive system. We have recently shown that promiscuous primate species have low index to ring finger ratios, while monogamous species have high ratios," said Emma Nelson, from the University of Liverpool's School of Archaeology, Classics and Egyptology.
"Although the fossil record is limited for this period, and more fossils are needed to confirm our findings, this method could prove to be an exciting new way of understanding how our social behaviour has evolved," she added.
"Developing novel approaches, such as finger ratios, can help inform the current debate surrounding the social systems of the earliest human ancestors," said Dr Susanne Shultz, from the Institute of Cognitive and Evolutionary Anthropology at the University of Oxford. (ANI)