Nature News mentions a new study on Homo floresiensis that concludes that the fossil is that of a microcephalic modern human. The study is actually published in PNAS (and if someone could send me a copy I would appreciate it – my email is in the about tab).
According to Nature News the team:
First, they scanned the cranial spaces of 21 human children suffering from microcephaly and compared them to measurements from 118 unaffected children.
The researchers found that two specific measurements — cerebellar protrusion (how far the base of the brain projects backwards) and relative frontal breadth — could be used to discriminate between microcephalics and unaffected children.
The team then made similar comparisons between endocasts of skulls of 10 microcephalic humans, 79 unaffected humans, 17 individuals of the human ancestor Homo erectus, 4 individuals from the human ancestor Australopithecus, and the H. floresiensis fossil. They report that the H. floresiensis cranium overlapped most with the measurements collected from microcephalics and Australopithecus.
Criticisms of the study rest, as you can imagine, on this last point…