A study of the full genetic code of a common human virus offers a dramatic confirmation of the "out-of-Africa" pattern of human migration, which had previously been documented by anthropologists and studies of the human genome.
The virus under study, herpes simplex virus type 1 (HSV-1), usually causes nothing more severe than cold sores around the mouth, says Curtis Brandt, a professor of medical microbiology and ophthalmology at UW-Madison.
When Brandt and co-authors Aaron Kolb and Cécile Ané compared 31 strains of HSV-1 collected in North America, Europe, Africa and Asia, "the result was fairly stunning," says Brandt.
"The viral strains sort exactly as you would predict based on sequencing of human genomes. We found that all of the African isolates cluster together, all the virus from the Far East, Korea, Japan, China clustered together, all the viruses in Europe and America, with one exception, clustered together," he says.
"What we found follows exactly what the anthropologists have told us, and the molecular geneticists who have analyzed the human genome have told us, about where humans originated and how they spread across the planet."