Chimpanzees usually walk on four feet, but rise to two feet when fighting for meals, according to researchers who claim that the human’s closest relative may have evolved the stance to run off with armfuls of food. And, this has helped to ensure their survival even when resources were scarce, says a team from the University of Cambridge and Japan’s Kyoto University.
In fact, the researchers believe the benefit of “first-come, first-served” and getting a bigger share of scarce food supplies could, over a long period of time, have led some of our earliest “hominin” ancestors to evolve into bipedal primates — walking on two legs permanently instead of four. “Bipedality as the key human adaptation may be an evolutionary product of this strategy over time. Ultimately, it set our ancestors on a separate evolutionary path,” William McGrew, who led the team, was quoted by the Daily Mail. The findings, published in the Current Biology journal, suggests that our earliest hominin ancestors may have lived in shifting environmental conditions where certain resources were not easy to come by. For their research, the team conducted two studies of chimpanzees in Bossou Forest in Guinea, west Africa, finding that when supplies of highly prized coula nuts were scarce, the chimps were more likely to walk on two feet in an attempt to carry off more in a single trip.
They also found when the chimpanzees went crop raiding, 35 per cent of their activity involved bipedal movement, and “once again, this behaviour appeared to be linked to a clear attempt to carry as much as possible in one go”. They believe that over time, intense bursts of bipedal activity in early hominins may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong.