Out of Eurasia, a great primate evolutionary bottleneck?

On the road to our modern human lineage, scientists speculate there were many twist and turns, evolutionary dead ends, and population bottlenecks along the way. But how large were population sizes of common ancestors of the great apes and humans, and does the genetic analysis support the prevailing views of a great bottleneck in primate evolution?

Using inferred evolutionary rates of more than 1400 genes and ancestral generation times, Professor Carlos Schrago and colleagues trace population histories backwards across evolutionary time to estimate population sizes for common ancestors. Their results show that the population sizes of lineages leading to human and chimpanzees dramatically shrunk over evolutionary time, from approximately 1,200,000 in number to 30,000.

This population reduction coincides with bio-geographical data that suggests a great ape ancestral migration event from Eurasia to Africa during the late Miocene period, from approximately 12 to 5.5 million years ago, with a five-fold reduction in effective population size between the ancestor of the Eurasian and African great apes and the ancestor of African great apes alone, suggesting that the Homininae diversified after a dispersal event from an Eurasian ancestor. phys.org

The article appears in the advanced online edition of Molecular Biology and Evolution.


Actualización 24-10-13. Out of Eurasia: El ancestro de los grandes simios africanos migró desde Eurasia (B&W2)
Carlos G. Schrago ha inferido los tamaños de población efectiva de los antepasados ​​antropoides del linaje humano - chimpancé utilizando conjuntos de secuencias codificantes y no codificantes de unos 1.400 genes.

Según sus conclusiones, en el linaje ancestral de Anthropoidea y la de Homo y Pan se puede apreciar un patrón general de disminución del tamaño de la población. La disminución más abrupta en la población, un cuello de botella genético de unos 30.000 indiviudos durante el Mioceno tardío (12-5,5 Ma), coincide con datos biogeográficos que sugieren un evento de migración de los grandes simios desde Eurasia hacia África y la separación filogenética del ancestro de los grandes simios africanos.