Yesterday the Journal of Human Evolution released a new paper by Rhonda Graves and colleagues, titled “Just how strapping was KNM–WT 15000?” [1]. The paper challenges almost 25-year-old estimates for the body size of this important 1.5 million year old skeleton.
For all this time, the textbooks have reported that early Homo in Africa had the same tall and elongated physique as current East African people like the Maasai. The new paper says that the textbooks are wrong -- the skeleton doesn't represent an individual who would have grown to be 6'1" (185 cm), instead it was near the end of its growth trajectory, for an adult height of around 5'4" (163 cm).
That's a pretty massive change, and when the authors presented this work at the AAPA meetings last spring, it wasn't without controversy. So naturally we should look closely at the paper, understand its conclusions, and assess what this new estimate means for our understanding of early Homo. As you might guess from reading some of my earlier posts, I've been thinking that the body sizes of the rest of the Pleistocene record add up to a fairly simple picture. One of the few outliers from this picture was KNM-WT 15000. I'm inclined to think that the new estimate fits the bigger picture -- for example, I wrote this spring about "Shrinking erectus".