Bones never lie

How evolutionary medicine impacts modern medical understandings.

AN ANTHROPOLOGIST at the Dan David Center for Human Evolution and Biohistory Research in the middle of an excavation. (photo credit: Courtesy)
AN ANTHROPOLOGIST at the Dan David Center for Human Evolution and Biohistory Research in the middle of an excavation.
(photo credit: Courtesy)
As anthropologists say, bones never lie.
Scientists at Tel Aviv University’s Dan David Center for Human Evolution and Biohistory Research take this a step further. They believe that research conducted on Tel Aviv University’s Biological Anthropology Collection of unique specimens gathered throughout the Levant over 80 years paint a detailed and accurate picture of ancient life ranging from demography, health and diet, to the division of labor, religious beliefs, ancestral cult and much more.
Now, TAU anthropologists are using this research to demonstrate that the interaction between our biological and cultural development can teach us a lot about the emergence of disease – how and why diseases evolved and why they disappeared.
According to the Dan David Center’s director, Prof. Israel Hershkovitz, such findings could have major implications not only for anthropological understanding but for enhancing human health in modern times.
“We call this evolutionary medicine,” explained Hershkovitz, who also directs TAU’s Shmunis Family Anthropology Institute, which provides cutting- edge lab equipment for specimen analysis. “Many of the diseases that modern people suffer from today are due to our evolutionary history, to the way our body evolves over time.
Evolutionary medicine tries to answer the question of why our anatomy and physiology were shaped in ways that leave us susceptible to so many diseases.”
Hershkovitz said that today’s rapid changes in the environment, culture and technology are too fast for human bodies to modify and adapt themselves, thus exposing modern people to many diseases rarely encountered by historic populations.
Dr. Hila May is a physical anthropologist and a member of the Dan David Center, which is housed at TAU’s Steinhardt Museum of Natural History. Her research focuses on ancient populations and their relation to modern humans.
She explained that the agricultural revolution – when the last hunter-gatherers of the Levant were transformed into a farming community – had the greatest impact on human life, including health, physical stress and diet.
“We became sedentary,” May said. “Our diets changed, too.”
Essentially, food became softer, reducing the loads applied on our jaws. This considerably impacted the size and shape of the jaws, which became smaller, leaving less room for teeth.
“It is probably why almost every second child needs to see an orthodontist,” said May. “We don’t have enough room for our teeth in our jaws, so our teeth are too crowded and tend to rotate or deviate from the dental arch.”
This can also be seen with the shape and size of women’s pelvis bone, which relates both to the human adaptation from walking on four limbs to walking on two legs (bipedalism), and the need to accommodate for growing brain size and larger heads during delivery.
“There are contradictory demands from the pelvis,” explained Hershkovitz. “To be able to deliver babies with big heads, you need a very wide pelvis. But the wider the pelvis, the less stable is your walking, so you need to balance between the demands of walking with stability and the demands for delivery. Two contradictory demands.”
Hershkovitz said another example is the way human bodies store fat. In prehistoric times, people starved from time to time, as there was less available food in certain seasons.
“Our bodies are built to store fat as a mean to overcome these bad times,” Hershkovitz said. “It is in our genes. People who worry about the high rate of obesity in modern children should be aware of this and use the information to help solve the problem more effectively.”
Hershkovitz said that modern doctors tend to treat symptoms (immediate cause of diseases).
Evolutionary medicine gives them the ability to relate to the ultimate cause of the disease.
“The research has clinical implications,” May stressed. “The better we understand diseases, the better the treatments will be.”
She said modern man did not “wake up one morning as we are today. Rather, “We are the product of a long process of both evolution and amazing social and technological development.”
She continued, “What is nice with anthropology is what we know today is not what we will know tomorrow. What we find in terms of fossils and the techniques we use to analyze those findings are progressing all the time.”
This article was written in cooperation with Tel Aviv University.