So, is this the end for Homo floresiensis?
I'm sure it won't be. But there are some things that I hope will
come to an end.
First of all, it is now abundantly clear that some kind of microcephaly can
explain the small size and small brain size of the LB1 specimen. Moreover, the specimen exhibits other very obvious signs of developmental pathology. It is a bad specimen on which to base the diagnosis of a new species; its most important features are quite plausibly caused by its manifest pathology.
The argument so far against pathology has been that it cannot explain other unique morphologies, like the lack of a chin, and Tomes' root, and so forth. But this paper shows that none of these other features are necessarily unusual for modern humans
, in the local and regional context. So that argument is dead, unless someone can show that there is some unique character to the combination of traits in the specimen. Since most of the features that would differentiate it from Homo erectus
-- purportedly due to endemic dwarfism -- are also shared with modern humans
, that seems like a problem for the species idea.
So I completely accept the argument that LB1 is pathological. A corollary is that the skeleton cannot be a convincing type specimen for a new species.
But this isn't only about LB1: there are the other small specimens. This paper makes clear that none
of the features of the LB6/1 mandible are outside the range of local peoples. This is not
a case of two specimens that must share some rare pathology; the paper argues that they are two specimens that share a regionally-common suite of characteristics. They aren't, in other words, unusual.