A new study of a common human virus may have confirmed the popular scientific belief that all humans originated from Africa.

University of Wisconsin (UW) at Madison professor of medical microbiology and ophthalmology Curtis Brandt and his colleagues studied the full genetic code of herpes simplex virus type-1 (HSV-1).

"The viral strains sort exactly as you would predict based on sequencing of human genomes," Brandt said in a press release. "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."

For the study, published online in the journal PLOS One, the researchers compared 31 strains of HSV-1 from North America, Europe, Asia and Africa.

"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," Brandt said.

Previous studies of HSV-1 could be misleading because many of them focused on a single gene or a small set.

"Scientists have come to realize that the relationships you get back from a single gene, or a small set of genes, are not very accurate," said Brandt.

The study of genetics is meant to uncover how organisms are related by measuring their sequence of "letters," or bases, of their genes. With the knowledge of how a genome changes, geneticists can build a family tree of sorts that show when there was a last common ancestor.

Human genome studies have previously stated that the ancient ancestors originated in Africa then migrated to Europe and Asia some 150,000 to 200,000 years ago.

The researchers broke the HSV-1 genome into 26 pieces and made a family tree for each part. Next, they created a network of trees with all the pieces of the genome.

"There is a population bottleneck between Africa and the rest of the world; very few people were involved in the initial migration from Africa," Brandt said. "When you look at the phylogenetic tree from the virus, it's exactly the same as what the anthropologists have told us."