15 percent of healthy Amish octogenarians have “haplogroup X,” a genetic pattern within the mitochondria, which are the regions of cells that generate energy and help guard against deterioration.

One of the world's greatest genetic mysteries is how a DNA marker present in Europe reached North America, leaving no clear trail through Siberia or Alaska. Scientists have been baffled by how ...

Figure 2: Maximum likelihood network inferred from the haplotype frequencies reported in Table 1. Three mutually reinforcing mutations, M42, M94 and M139 (two transversions and a 1-bp deletion), ...