Once again reviving the debate over the nature of the Flores hominid, a new study published this week in the Proceedings of the National Academy of Sciences compares skull scans from various samples, including microcephalic humans and other hominids, and suggest that the H. floresiensis is a microcephalic human rather than a separate species.
Taking the measure of a hobbit
Science News, 08 August 2011
‘Hobbit’ just a deformed human?
Nature, 08 August 2011
Craniometric ratios of microcephaly and LB1, Homo floresiensis, using MRI and endocasts
Proceedings of the National Academy of Science, 08 August 2011
doi:10.1073/pnas.1105585108
The designation of Homo floresiensis as a new species derived from an ancient population is controversial, because the type specimen, LB1, might represent a pathological microcephalic modern Homo sapiens. Accordingly, two specific craniometric ratios (relative frontal breadth and cerebellar protrusion) were ascertained in 21 microcephalic infants and children by using MRI. Data on 118 age-equivalent control (normocephalic) subjects were collected for comparative purposes. In addition, the same craniometric ratios were determined on the endocasts of 10 microcephalic individuals, 79 normal controls (anatomically modern humans), and 17 Homo erectus specimens. These ratios were then compared with those of two LB1 endocasts. The findings showed that the calculated cerebral/cerebellar ratios of the LB1 endocast [Falk D, et al. (2007) Proc Natl Acad Sci USA 104:2513–2518] fall outside the range of living normocephalic individuals. The ratios derived from two LB1 endocasts also fall largely outside the range of modern normal human and H. erectus endocasts and within the range of microcephalic endocasts. The findings support but do not prove the contention that LB1 represents a pathological microcephalic Homo sapiens rather than a new species, (i.e., H. floresiensis).
