Ancient and modern humans 'may have interbred'
Ancient and modern humans may have interbred, a study published in the journal Plos One suggests.
Scientists analysed human remains found in West Africa, which date to 13,000 years old.
Even though this was a time when modern humans were fully in existence, the team found that the cranial shape of the skull was primitive and was more closely related to African fossils that date to 140,000 years old than to modern humans.
Here the Natural History Museum's Professor Chris Stringer compares a replica of one of the skulls with both older and more modern skulls, and describes why this indicates that ancient and modern humans may have co-existed and interbred.
16 Sep 2011