We may have 95 to 99.4% of our DNA in common, but when it comes to the type of mates Chimpanzees and humans look for, it seems that there’s where the real difference lies.
A new study on chimps by researchers at Boston University and Harvard University has found that when it comes to finding their mates, male chimps the older their females are, the better.
The researchers found that the reason why, unlike their human cousins, chimps prefer older females as mates over younger females, may lie in the fact that whereas chimpanzees participate in a relatively promiscuous mating system, humans form unusually long-term mating bonds, thereby making young females more valuable as mates with greater reproductive potential.
As a part of the research, the boffins studied male mate preferences within the Kanyawara chimpanzee community in Kibale National Park in Uganda.
They found that, in contrast to humans, male chimpanzees prefer older females to younger ones, and that compared to younger females, older females were more likely to be approached for copulation, were more often in association with males during estrous periods, copulated more frequently with high-ranking males, and gave rise to higher rates of male-on-male aggression in mating contests.
Theoretical explanations for the preference of human males for young females as mates include the facts that humans tend to form long-term mating partnerships, and that female fertility is limited by menopause and, therefore, age.
The findings, in addition to supporting the idea that long-term pair bonding and menopause may contribute to the preference of human males for young females, also suggest that this characteristic may be an evolutionarily derived trait that arose in the human lineage sometime after the lineages giving rise to humans and chimpanzees diverged.