October 10, 2006

New Anatomical Record on Flores hominid

On the heels of the recent paper on PNAS about the Flores hominid (aka "Hobbit"), a new paper in the Anatomical Record also questions the validity of Homo floresiensis. Here is the press release from the Field Museum:
CHICAGO -- What may well turn out to be the definitive work in a debate that has been raging in palaeoanthropology for two years will be published in the November 2006 issue of Anatomical Record.

The new research comprehensively and convincingly makes the case that the small skull discovered in Flores, Indonesia, in 2003 does not represent a new species of hominid, as was claimed in a study published in Nature in 2004. Instead, the skull is most likely that of a small-bodied modern human who suffered from a genetic condition known as microcephaly, which is characterized by a small head.

"It's no accident that this supposedly new species of hominid was dubbed the 'Hobbit;'" said Robert R. Martin, PhD, Curator of Biological Anthropology at the Field Museum and lead author of the paper. "It is simply fanciful to imagine that this fossil represents anything other than a modern human." The new study is the most wide-ranging, multidisciplinary assessment of the problems associated with the interpretation of the 18,000-year-old Flores hominid yet to be published. The authors include experts on:

* scaling effects of body size, notably with respect to the brain: Dr. Martin and Ann M. MacLarnon, PhD, School of Human & Life Sciences, Roehampton University in London;
* clinical and genetic aspects of human microcephaly: William B. Dobyns, PhD, Department of Human Genetics, University of Chicago; and
* stone tools: James Phillips, PhD, Departments of Anthropology at the University of Illinois at Chicago and the Field Museum.

This is just one of four separate research teams that have recently published evidence indicating concluding that the Flores hominid is far more likely to be a small-bodied modern human suffering from a microcephaly than a new species derived from Homo erectus, as was claimed in the original Nature paper.

Significantly, the second most recent publication to conclude that the "Hobbit" was microcephalic--another multidimensional study that was published in the September 5, 2006, issue of Proceedings of the National Academy of Sciences--includes a co-author who was also a co-author of the original publication in Nature. That scientist, R.P. Soejono of the National Archaeological Research Center in Jakarta, Indonesia, now writes that the Flores hominid was microcephalic rather than a new hominid species.

The Anatomical Record Part A Published Online: 9 Oct 2006

Flores hominid: New species or microcephalic dwarf?

Robert D. Martin et al.


The proposed new hominid "Homo floresiensis" is based on specimens from cave deposits on the Indonesian island Flores. The primary evidence, dated at ~18,000 y, is a skull and partial skeleton of a very small but dentally adult individual (LB1). Incomplete specimens are attributed to eight additional individuals. Stone tools at the site are also attributed to H. floresiensis. The discoverers interpreted H. floresiensis as an insular dwarf derived from Homo erectus, but others see LB1 as a small-bodied microcephalic Homo sapiens. Study of virtual endocasts, including LB1 and a European microcephalic, purportedly excluded microcephaly, but reconsideration reveals several problems. The cranial capacity of LB1 ( ~400 cc) is smaller than in any other known hominid


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