Friday, October 18, 2013

New Dmanisi cranium increases variation, questions early Homo species diversity

The team from the site of Dmanisi in Georgia just published the description of their "Skull 5", which represents the fifth well preserved skull from this important 1.8 million year old site from the Republic of Georgia.

Skull 5: credit  Georgia National Museum, AP
This skull is super important, because it is quite different from the other four Dmanisi skulls in that is has a massive face and jaw, and just a tiny brain at about 550cc. Thus, the authors argue that the Dmanisi sample from a single place and a relatively short time interval encompasses virtually all of the variation found in early Homo specimens from Africa. This would imply that the proposed species diversity in early Homo is not really species diversity at all, unless you want to split the Dmanisi specimen into multiple species.

The specimen is getting TONS of well-deserved press attention, but much of the coverage is predictably sensationalist....claiming that this skull overturns what we thought we knew about the human family tree.  A more accurate description might be that this skull offers fresh evidence which is lending new support to a long-standing idea in paleoanthropology (i.e. that early Homo is characterized best as one species).