A chimpanzee is seen in Douala Edea National Park in the Littoral region, Cameroon, on April 20, 2022. (Photo by Kepseu/Xinhua)
BEIJING, Sept. 15 (Xinhua) — A Chinese research group has come up with a new hypothesis on the evolution of today’s primates: the ancestral species took on their typical appearance when they adopted a more carnivorous diet by ambushing prey in trees.
Primates, including monkeys and humans, are characterized by grasping hands and feet, reduced claws, and closer eye sockets that give them a greater ability to look forward.
A well-known theory proposed that the converging orbits of the common ancestor of tree-dwelling, insect-eating primates could help them locate prey. But it’s hard to explain why other predators like wolves and eagles didn’t develop that facial feature.
Zoologists at Northeastern Normal University analyzed a large number of non-primate species with high orbital convergence, such as cats, night owls and flatfish.
They found that these animals are all ambush predators, suggesting that our ancestors’ appearances adapted as they learned to launch sneak attacks, according to the study published Thursday in the peer-reviewed journal Science Advances.
In addition, they recorded the sounds of the squirrels climbing trees before and after their claws were declawed. It turned out that the clawless squirrels were significantly quieter climbers, an experiment that may explain why the ancestors of primates that still hunted evolved reduced claws to relax vigilance over prey.
“The work is an important attempt to answer the controversial question of how diet may have influenced primate evolution,” Wu Yonghua, a professor at Northeast Normal University and one of the corresponding authors of the paper, told Xinhua. ■