"Duck Season!" "Rabbit Season!"

There's a new paper out in the Proceedings of the Royal Society B about the ever-controversial Homo floresiensis, the authors of the paper arguing that the fossils representing this new species are actually "myxoedematous endemic cretins," of the species Homo sapiens. The condition the authors propose is expressed by the Flores hominid is generally caused by a lack of iodine in the diet, such a deficiency causing the thyroid gland to produce improper amounts of hormones associated with bone growth and brain size, resulting in mentally-impaired individuals of small stature. So far the paper has been generally panned (see the responses of Greg and Afarensis), and it seems to be just another shot in the "Duck season!" "Rabbit Season!"-type argument over whether Homo floresiensis is a real species or the individuals identified so far are just pathological humans (the previous debate that created similar headlines in pop science publications centered on microcephaly, a claim that has been refuted by Dean Falk).

As if the new Proceedings didn't stir enough of a feeling of deja vu to begin with, the debate over Homo floresiensis would not be the first time that a fossil hominid was claimed to be a pathological human specimen. In the years prior to the publication of Darwin's On the Origin of Species by Means of Natural Selection, fossils of Neanderthals started to appear in Europe. At the time, however, they didn't seem to be different enough from that of Homo sapiens to consider them to be a distinct species of human, some authorities claiming that the Neanderthal remains were nothing more than the bones of "a rickety 'Mongolian Cossack,' belonging to one of the hordes driven by Russia, through Germany, into France in 1814." Although such ideas were more widespread during the early days of paleoanthroplogy when it was difficult to determine how old the fossils were (and the fossils themselves were rare), they do bear a striking resemblance to the more modern debate.

When Darwin published On the Origin of Species by Means of Natural Selection he ran into opposition from a variety of critics, and in Germany one of the leaders of the opposition to evolution was Rudolf Virchow. Unfortunately I do not possess any of Virchow's actual work, but his claims have been mentioned in a number of anthropological works. In the 1896 book Primary Factors of Organic Evolution, paleontologist E.D. Cope addressed a Popular Science Monthly piece Virchow had published in January, 1893;

Professor Virchow in a late address has thrown down the gage to the evolutionary anthropologists by asserting that "scientific anthropology begins with living races," adding "that the first step in the construction of the doctrine of transformism will be the explanation of the way the human races have been formed," etc. But the only way of solving the latter problem will be by the discovery of the ancestral races, which are extinct. The ad captandum remarks of the learned professor as to deriving an Aryan from a Negro, etc. remind one of the criticisms directed at the doctrine of evolution when it was first presented to the public, as to a horse never producing a cow, etc. It is well known to Professor Virchow that human races present greater or less approximations to the simian type in various respects. ... Professor Virchow states that the Neanderthal man is a diseased subject, but the disease has evidently not destroyed his race characters; and in his address he ignores the important and well-authenticated discovery of the man and woman of Spy. These observations are reinforced by recent discovery of a similar man by DuBois at Trinil in the island of Java [Homo erectus].

Indeed, Virchow proposed that the Neanderthal specimen he examined was afflicted by rickets and arthritis, as well as suffering a number of blows to the head. Humans in an uncivilized state could not have survived such punishment, so the remains had to be from a modern (if aberrant) representative of Homo sapiens. Being that he was a leading cellular pathologist his word seemed to be the standard on the subject, but this did not prevent others from proposing their own interpretations. Strong racist tendencies also obscured the true identity of the Neanderthal fossils, and in Man, Time, and Fossils (1953) author Ruth Moore states;

A physician learnedly proved that the creature from which it came was affected by "hypertrophic deformation." Another described it as that of "an individual affected with idiocy and rickets." A prominent French anthropologist contributed the theory that it was the skull of "a powerfully organized Celt, somewhat resembling the skull of a modern Irishman with low mental organization. Equally remarkable was the opinion of a German authority; the remains, he argued, were those of "one of the Cossacks who came from Russia in 1814."

(Also note the racist perspective in Cope's quote reproduced above.)

Perhaps the most fanciful explanation was the narrative constructed by an anatomist named Mayer. According to Man's Evolution (1965);

The Neanderthaler's left elbow had apparently been broken early in life, and this, claimed Mayer along with the pain cause by the rickets which the individual was said to have suffered since childhood, had caused him to pucker his brow in a permanent frown which was eventually ossified in the skull's heavy brow ridge. Mayer continued with his free-wheeling deductions by pointed to the bowed femora (thigh bones). There, he claimed, were the result of having spent long years in the saddle.

The difficulty in dating the Neanderthal finds, racist leanings, and anti-evolutionary reactions helped to form such conclusions, but even scientists in Darwin's own camp doubted the significance of the Neanderthal fossils to evolution. In Man's Place in Nature, T.H. Huxley wrote;

In no sense, then, can the Neanderthal bones be regarded as the remains of a human being intermediate between Men and Apes. At most, they demonstrate the existence of a Man whose skull may be said to revert somewhat towards the pithecoid type-just as a Carrier, our a Pouter, or a Tumbler [all breeds of pigeons], may sometimes put on the plumage of its primitive stock, the Columba livia.

Huxley was optimistic that older remains would yet be found, although he could offer no insight into where researchers should begin to look. Willian King, however, did not believe that the Neanderthal fossils fell within the range of human variation and dubbed them Homo neanderthalensis, a designation that has been borne out by the evidence accumulated since King proposed the name in 1864. Still, there are perhaps no group of fossils as controversial as human fossils, and even from the very beginning of paleoanthropology the discipline has been filled with controversies as to the identity our closest extinct relatives.

Going back to the new Homo floresiensis paper, other bloggers have already deconstructed it in more detail than I feel that I'm capable of (again, see the posts by Greg and Afarensis). What concerns me, though, is that the paper was written and published without the authors actually examining the Flores fossils. Even worse, they use a low-resolution screen grab from a Horizon program called "The mystery of the human hobbit," as part of the data to back up their hypothesis. (This is one of my pet-peeves about things going digital. It's all too easy to get screen grabs or low-resolution scans and slap them in books and papers. I'm sick of seeing pictures that are ragged with pixels or look like they are photographs of a television screen.) These realizations undermine the whole paper, a tenuous connection of second-hand data that will require an actual examination of the material to either confirm or refute.

Overall, the case presented in the Proceedings paper is flimsy, at best, and will require study of the actual fossils (not just images from other papers or television shows). Maybe the researchers are on to something, but I think this new article is a representation of extremely sloppy research and I have to wonder how it made it through peer-review.

Obendorf, P.J., Oxnard, C.E., Kefford, B.J. (2008). Are the small human-like fossils found on Flores human endemic cretins?. Proceedings of the Royal Society B: Biological Sciences, -1(-1), -1--1. DOI: 10.1098/rspb.2007.1488