hy mtDNA travels directly from mother to offspring without recombining, as nuclear DNA does, is an evolutionary mystery, but as a consequence of its maternal passage, researchers trace the mtDNA of every person in the world back to a hypothetical Mitochondrial Eve, a common ancestor who lived in Africa 200,000 years ago. Over time, as Eve’s female progeny moved into Europe and beyond, her mtDNA mutated in ways that did not cause disease and, in fact, seemed to confer metabolic advantages in certain environments: People who lived near the poles, for instance, ended up with a different mtDNA type, via natural selection, than those who lived at the Equator; the same thing happened at high and low altitudes. MtDNA types are also associated with a person’s likelihood of developing certain diseases, including cancer, or characteristics like obesity, athleticism and longevity — though it’s not apparent why. Part of the reason may have to do with the fact that mitochondria send and receive signals to and from the nucleus that influence how the genes there are expressed. Some researchers claim that interfering with mitochondria could interrupt that communication, adding mitochondrial problems to the human gene pool instead of subtracting them
Posted on: Mon, 30 Jun 2014 23:34:20 +0000