From U Wisconsin paleoanthropologist John Hawks:
Bernard Wood’s research group has a new paper on brain size evolution in hominins, led by Andrew Du in Proceedings of the Royal Society, Series B: “Pattern and process in hominin brain size evolution are scale-dependent”.
In this paper, I notice that the researchers have done a really weird thing: Their analyses include only hominin fossils before 500,000 years ago.
The specimens reflect every hominin species from Australopithecus afarensis up to “Homo heidelbergensis”. Modern humans and Neanderthals have been left out of the dataset—they don’t fall within the pre-500,000-year time range.
On the basis of this dataset, the authors conclude that the entire hominin lineage is compatible with a single pattern of gradual evolutionary increase over time.
Charts are offered by way of illustration.
There are two species entirely missing from the data examined by Du and colleagues. The fossil records of endocranial volume in Homo naledi and Homo floresiensis both date to the last 300,000 years. When you include them, they both reject the notion of gradual monotonic increase in brain size. More.
We are used to governments’ disappearing monster deficits (and, to be honest, in some cases, disappearing people) this way. It feels squishier when scientists do it. Unless, of course, evolutionary biology isn’t really a science anymore. More a form of Darwinian storytelling where the preferred narrative is chosen…
Also note bornagain77’s supplementary information below.
See also: John Hawks on human evolution: Free chapter from book on evolution from Princeton U