Modern day humankind is characterized by lightweight skeletons as compared to early hominids or primates in general. This is because human race got sluggish with the arrival of agriculture, researchers say. This implies that the way we live shapes our body structure more than we think.
Habiba Chirchir, an organic anthropologist teamed up with other researchers from the Smithsonian’s National Museum of Natural History and decided to examine different primates’ bones, humans included. When analyzing the finishes of bones close to the joints, an area inside the bone that is generally spongy-like, they discovered that the thickness of this spongy area was weaker than that in same bones of chimpanzees or orangutans.
At that point, Chirchir thought it appropriate to dig even deeper and examine fossil bones, the skeletons of early hominids that were available. The team of researchers speculated that humankind got thinner bones a few million years back, more or less at the time Homo Erectus moved out of Africa. Homo Erectus is the earliest hominid that resembles most to humans. Why then? Because walking long distances would have been easier if the bones were less heavy, alleged Chirchir.
However, the examination of a group of human fossils proved the team wrong. The lead scientist realized, to her surprise, the theory she put forth was not correct. The old bones revealed that the change in skeleton density happened later in human history.
Accordingly, the slim bones started to develop only about 12,000 years ago, when humans started to pursue agricultural practices. That was the time when our ancestors decided to abandon a seeker -gatherer life which involved a lot of physical effort and settled in small rural communities.
The Proceedings of the National Academy of Sciences published this Monday a full report on the researchers’ inquiry together with a different study, done by another group of scientists that practically reached the same conclusion.
The other researchers examined the skeletons of humans that lived about 1,000 years ago in villages and whose main occupation was farming. Then, they mirrored the results of this analysis with an analysis of the skeletons of those who lived close by, but had as main occupation hunting.
Their results showed that the bones of individuals in the agricultural communities were less solid and less thick than those of hunters. Even more interesting, the hunters’ bones quality was practically identical to that of other primates.
According to Timothy Ryan, associate professor of anthropology at Penn State University, the change in bones structure should be considered a side effect of switching from a continuous mobility to a more sedentary way of life. He is certain that physical action and versatility are key factors that influence bone density.
Image Source: GPB News