Dispute over Flores people continues
The species status of the Flores man Homo floresiensis, newly described in October 2004, remains controversial. While anthropologists from the Field Museum in Chicago still assume that the mysterious dwarf from the Indonesian island of Flores is an anatomically modern human (Homo sapiens) who suffers from a pathological reduction of the skull - a so-called microcephaly - suffered, the discoverers of the fossil vigorously reject this interpretation.
As early as March 2005, Dean Falk of Florida State University examined the 18,000-year-old skull of the LB1 type specimen of Homo floresiensis on behalf of the discoverers, Peter Brown and Michael Morwood of the University of New England, and found a Microcephaly ruled out. However, Robert Martin and his colleagues at the Field Museum now question this conclusion .
They argue that the tiny skull volume of 400 cubic centimeters cannot be explained by normal dwarfism – as can occur in species isolated on islands – since the brain mass is only slightly reduced. For their part, Brown and Morwood had hypothesized that Homo floresiensis was descended from Homo erectus and dwarfed by the remoteness of the island of Flores.
Martin and Co also question the origin of Homo erectus. The stone tools found with the fossils were so highly developed that they could only have come from Homo sapiens.
As their most powerful weapon, the researchers use the comparison skull that Falk used to refute the microcephaly hypothesis. In true detective work, the Chicago scientists tracked down the fate of the skull: According to this, it dates from 1907 and originally belonged to the collection of the State Museum of Natural History in Stuttgart. It is the remains of a boy named Jakob Moegele from the village of Plattenhardt who suffered from microcephaly and died at the age of ten. However, because LB1 was clearly an adult individual, the researchers argued that comparison was not valid.
Instead, the researchers working with Martin present several comparative skulls from adult microcephaly patients. And these skulls, according to the researchers, are strikingly similar to LB1. The Flores man could therefore have been nothing other than a microcephalic Homo sapiens.
Dean Falk and her colleagues reject this chain of arguments . In their view, the brain-to-body volume ratio in Homo floresiensis is well within the range found in modern humans, including pygmies, great apes, and fossil hominids such as Homo erectus and Australopithecus.
They remark smugly that it hadn't escaped their notice that their reference skull was that of a juvenile specimen and that they were "happy to learn that it was in fact a ten-year-old boy". Nevertheless, Jakob Moegele's skull is typical of microcephaly, as comparisons with other skulls show: the imprints of the brain on the inside of the cranial bones in microcephalics show similar structures that are not found in LB1.
Falk et al. conclude by noting that their opponents only presented rough drawings of the comparative skulls, missing important details. Without these details, however, the assumptions made by Martin and colleagues remained "untenable".