Evidence for Menopause in Wild Chimpanzees

Few mammalian species exhibit menopause. It is thought that humans evolved into this state of post-reproductive old age in part because older individuals can help to enhance the reproductive fitness of their direct offspring. This view is known as the "grandmother hypothesis". The same behavior is observed in orcas, one of the few other mammals to exhibit menopause. Researchers here provide evidence for chimpanzees to undergo menopause, which is a strike against the grandmother hypothesis, as chimpanzee elders do not assist their offspring in this way. A team of researchers studying the Ngogo community of wild chimpanzees in western Uganda's Kibale National Park for two decades has published a report showing that females in this population can experience menopause and postreproductive survival. Prior to the study these traits had only been found among mammals in a few species of toothed whales, and among primates only in humans. These new demographic and physiological data can help researchers better understand why menopause and post-fertile survival occur in nature, and how it evolved in the human species. The grandmother hypothesis has been used to explain the existence of human postmenopausal survival, proposes that females in their postreproductive years may be able to pass on more of their genes by helping to raise the birth rates of their own children or by caring directly for grandchildren, thereby increasing grandchildren's odds of survival. And indeed...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs