Tuesday, June 5, 2012

Rethinking the "Out of Africa" Hypothesis--Redux

Several months ago, I had linked to an article that discussed some challenges to the "out of Africa" theory of evolution. So, it was with interest that I read this article today that states that our pre-hominid (i.e., anthropoid) ancestors of nearly 40 million years ago also were from Asia:
The birthplace of the human race is Asia - our earliest ancestors came to Asia in a huge migration 37-38 million years ago, before they evolved into present-day apes and humans.

A team of palaeontologists in Myanmar has found the tooth of a pre-human ancestor - afrasia djijidae, so-called because it forms a missing link between Africa and Asia - that is very similar another early ancestor found in Libya.

Four similar teeth were found after six years of sifting through sediment - a find that helps seal Asia as the starting point for our species.

‘Not only does Afrasia help seal the case that anthropoids first evolved in Asia, it also tells us when our anthropoid ancestors first made their way to Africa, where they continued to evolve into apes and humans,’ says Chris Beard, Carnegie Museum of Natural History palaontologist.

He worked with an international team that included scientists from the University of Poitiers.

‘Afrasia is a game-changer because for the first time it signals when our distant ancestors initially colonized Africa. If this ancient migration had never taken place, we wouldn’t be here talking about it.’

Paleontologists have been divided over exactly how and when early Asian anthropoids made their way from Asia to Africa.

The trip could not have been easy, because a more extensive version of the modern Mediterranean Sea called the Tethys Sea separated Africa from Eurasia at that time. While the discovery of Afrasia does not solve the exact route early anthropoids followed in reaching Africa, it does suggest that the colonization event occurred relatively recently, only shortly before the first anthropoid fossils are found in the African fossil record.

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