The Investigation Discloses The Link Between The Primate Knuckles And The Use Of The Hand

The research carried out by the University of Kent has found differences between the knuckle joints of primates that will allow a better understanding of the ancient use of the human hand.

Using samples from the Powell-Cotton Museum in Birchington-on-Sea (United Kingdom), as well as samples from Germany, Belgium and the United States, a team led by the School of Anthropology and Conservation (SAC), PhD student Christopher Dunmore, examined the inner bone. Structure, called trabecula or cancellous bone, of great apes.

Trabecular bone is a honeycomb structure that is found inside most bones and changes according to the use of bone throughout life. When preserved in fossils, researchers can learn more about how ancient monkeys and humans moved and interacted with their environment.

The study compared the internal bony structure of the knuckle joints in the hands of chimpanzees, bonobos, orangutans and gorillas, to assess whether this bone structure records how these monkeys moved when they walked with knuckles on the ground or hanging from trees.

The researchers found that the knuckle joints of orangutans were consistent with the knuckle flexion when grasping the branches, while the joints of the chimpanzees, bonobos and gorillas were consistent with knuckle gait, the most frequent forms in that these animals move in their respective environments

The information now will allow scientists studying the fossils to better understand whether ancient humans were swinging from trees or walking on the ground.

Mr. Dunmore said: "For the first time we see interesting internal bony patterns that differentiate the subtle differences between chimpanzees and gorillas that walk on the knuckles, as well as the arboreal grip on orangutans, this is important because when we find old fossils of human hand that keep their interior structure, we can calculate if they were probably swinging from the trees during their life or if they were walking on the ground like humans today. "

The study, entitled metacarpal trabecular bone varies with the different positions of the hands used in hominid locomotion (Christopher Dunmore, Dr. Ameline Bardo, Professor Tracy Kivell and Dr. Matthew Skinner, Research Center of Skeleton Biology, SAC, University of Kent) was published in the Journal of Anatomy.

By: Preeti Narula

Content: https://www.sciencedaily.com/releases/2019/05/190529122145.htm