Gene, fossil data back diverse human roots
By Bruce Bower
Just how modern humans first proliferated remains a great mystery of anthropology. Several recent fossil and genetic studies support the influential notion that a small population of Homo sapiens in Africa around 100,000 years ago began to spread, replacing humanlike species such as Neandertals.
Two new investigations raise doubts about this out-of-Africa scenario. One, slated to appear in the Proceedings of the National Academy of Sciences, finds that ancient mitochondrial DNA retrieved from a 62,000-year-old Australian H. sapiens fossil differs greatly from the DNA of living people. This evidence is consistent with the multiregional theory of human evolution. Different mitochondrial DNA lineages could have flourished and then disappeared as modern H. sapiens evolved simultaneously in two or more parts of the world over the past 1 million to 2 million years.