![]() Surprisingly, female gorillas even gained more strength in certain bones with age than males did. Instead, both male and female gorillas maintained bone strength throughout their lives. Their bones did show some expected signs of aging, such as a thinning of bone walls and a widening of long bones, but as Ruff had suspected, they didn't have the same loss of bone mass and density-or overall bone strength-that humans do. The team scanned 34 male and female mountain gorillas ranging in age from 11 to 43, the upper end of a wild gorilla's life span.Įven the oldest gorillas showed no signs of osteoporosis, the researchers reported September 21 in the Philosophical Transactions of the Royal Society B. Using a miniature CT scanner, Ruff and his colleagues took detailed measurements of bones' mineral content and geometry. That could be true for our more distant evolutionary ancestors as well, and for our gorilla cousins. "The main factor here is just moving your own body weight," he says, which ancient people likely did more than people today. Physical exercise strengthens bones, particularly if it's weight-bearing, so perhaps our ancestors staved off bone loss through exercise, he hypothesizes. Since this seems to be a modern phenomenon, Ruff thought, maybe osteoporosis is not a biological inevitability but rather a result of modern lifestyles, at least in part. Today, both men and women experience steady bone loss with age starting in their 20s or 30s, with women showing a sharper loss Their bones also changed shape with age in ways that helped keep them strong. But early in his career, Ruff studied a prehistoric population from the American Southwest and found that while One hypothesis is that our ancestors simply didn't live long enough "Why is there this mismatch among older people," Ruff asks, "where your bones become too weak for the normal forces that you place on them?" It seems terribly disadvantageous for a species to become so brittle with age that even mild stress can cause a fracture, sometimes just by coughing. "Osteoporosis is a really interesting mechanical issue," Ruff says, and one that's perplexing from an evolutionary standpoint. Some of these gorillas were first observed in the wild by the late Dian Fossey, the famed anthropologist who founded the Karisoke Research Center, which is now part of the Dian Fossey Gorilla Fund International. A room lined nearly floor to ceiling with steel cabinets holds the gorillas' remains, each one linked to a catalog with everything researchers know about that individual-in many cases, not only when it was born and died but details of its activities and social life. Karisoke is the best place in the world to answer that question. "Gorillas and chimpanzees are our closest evolutionary relatives," he says, so he wanted to know whether they, too, experience osteoporosis with age. A professor emeritus at the Johns Hopkins Center for Functional Anatomy and Evolution, Ruff was particularly interested in understanding the evolution of osteoporosis, the weakening of bones linked to fractures in old age. Ruff had come to the Karisoke Research Center, where the skeletons of more than 100 wild mountain gorillas have been carefully collected, cleaned, and cataloged, to find out whether human and gorilla bones age differently. Image credit: Courtesy of Christopher Ruff
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |