Some of the newer use of mitochondrial DNA lineages is fascinating. From the latest research I've seen it puts the migration of modern man out of Africa to around 100,000 years ago. This line went east to India and south to Australia. At this time it is estimated that the sea level was some 60 to 100 meters lower, exposing an almost complete land bridge from India to Australia. Some of there descendent's intermixed with later migrations. Australia eventually lost its land bridge and the resulting isolation allowed for a less influenced line of people, the Aborigine. The second, and only other currently known of, line migrated to what is currently Mongolia at around 50,000 to 60,000 years ago. This line further developed into several offshoots. Some went to the new world, the native Americans. Current belief is over a land bridge, but ancient sea vessel's in china have been found that were capable of crossing the pacific. Another offshoot went on to become the Europeans. All very interesting.