As mentioned yesterday, Jebel Irhoud documents an early African Homo sapiens. The specimen represents mixture of archaic and modern features, such as an elongated braincase compared to the face and teeth, respectively. In a new paper published in Science Advances, researchers Simon Neubauer, Jean-Jacques Hublin and Philipp Gunz used CT scans to create virtual endocasts that approximate brain size and shape and compared them to other endocasts of various fossils and present-day humans. Their findings as outlined in the image below show that in the last 300,000 years or so, our brain shape changed to a more globular one from a elongated archaic form.
Two areas, the parietal lobes and the cerebellum bulged recently. Both areas function in spatial orientation, the parietal more aligned to the higher functions while the cerebellum more towards the lower ones, like coordination and balance. Curiously, these shape changes evolved some time between 100,000 and 35,000 years ago and independently of brain size — with endocranial volumes similar even the oldest Homo sapiens fossils from Jebel Irhoud falling within present-day variation of brain size. These changes parallel the gradual emergence of behavioral modernity as seen from the archaeological record.