Scientists mapped the complete genome of a half-million-year-old horse by extracting DNA from its bone, which was found preserved in the permafrost of the Canadian Arctic. It is the oldest-known full genome of any species. The finding also dates the origin of equines to 4 million years ago, 2 million years earlier than previously thought. The DNA extraction and analysis techniques may prove useful in examining the evolution of other species, including humans.
Published in Brief: