The first ancestors of non-African humans are believed to have moved across the Arabian Peninsula 130,000 years ago.
The researchers looked at "geography of potential migration routes, genetic data and cranial comparisons," a University of Tübingen news release reported.
The team determined the earliest migration out of Africa took place earlier than researchers had previously believed. A second trek to Eurasia was believed to have taken place about 50,000 years ago.
Modern humans are believed to be related to an African population that existed between 100,000 and 200,000 years ago.
A "decreasing genetic and phenotypic diversity" was seen in humans the farther they got from sub-Saharan Africa, this has been interpreted as indication of a single migration 50,000 to 75,000 years ago. This new study disputes the popular theory.
The new model suggests there were multiple dispersals, as opposed to just one. The researchers compared skull shapes, genetic data, and dispersal routes; they also "reconstructed population split times from both the genetic data and as predicted by each competing model," the news release reported.
Since each instance of dispersal was associated with a temporal and geographic the team was able to test these factors against "observed neutral biological distances between groups," the news release reported.
The first group of ancestors is believed to have left Africa 130,000 years ago and followed a coastal route to Australia and the West Pacific region. Another Asian population is believed to have descended from a later migration from Africa to northern Eurasia about 50,000 years ago.
"Both lines of evidence - anatomical cranial comparisons as well as genetic data - support a multiple dispersal model," University of Tübingen's Professor Katerina Harvati said in the news release.. "Australian aborigines, Papuans and Melanesians were relatively isolated after the early dispersal along the southern route,"
The researchers hope to improve these models in the future as well as determining what prompted the migrations.
