Thursday, 10 September 2009

Bad Science!

While browsing the Independent website yesterday evening I saw this article at the top of the Most Viewed list. An article entitled A skull that that rewrites the history of man is an attention-getter. But when I read the article by Science Editor Steve Connor and this accompanying piece also by Mr Connor I was frankly astounded. The first of the fossil remains in question were discovered near the medieval Georgian town of Dmanisi in 1991 (when Georgia was still a part of the Soviet Union). They were attributed to a new species, Homo georgicus, in a 2002 article in the journal Science (Vekua et al, 2002). Moreover the article is free to download to anybody and does not require a subscription to the journal.

Yet nowhere in either of Mr Connor’s articles does he mention that Homo georgicus has been in the public domain for so long. I’ve read both pretty carefully and they imply that this is a brand new discovery. Furthermore, both the Independent articles are dated 9 September 2009. It does sometimes happen that an old article will feature in a website’s “most viewed” list; this is not the case here.

Turning to the articles themselves, the content leaves a lot to be desired. They are full of phrases such as “conventional view of evolution” and “simple view” which (it is implied) has been overturned by the discovery of the Dmanisi remains. This is utter nonsense. Just about the only thing physical anthropologists ever agree on is to disagree! There is no “simple view” of human evolution that has begun to “unravel”. Rather the view is based on a jigsaw puzzle with pieces that have gradually been added, beginning in the 19th Century with the discovery of the Neanderthals and Java Man.

The “simple view” that Mr Connor alludes to is that Homo habilis evolved from a gracile australopithecine species, possibly A. afrarensis (“Lucy”); Homo erectus evolved from H. habilis and migrated into Eurasia, and that Homo sapiens and the Neanderthals both evolved from Homo erectus via an intermediate form sometimes known as Archaic Homo sapiens. This is a first order approximation that nobody has ever seriously believed represented the true picture.

Homo georgicus is probably an early form of Homo ergaster (“African Homo erectus”). We know that very soon after the appearance of H. ergaster in Africa, Homo erectus shows up in Java. There are two possible interpretations; firstly H. georgicus left Africa and died out, with Asian H. erectus arising from a subsequent migration of H. ergaster from Africa. The second – more likely – possibility is that Homo georgicus carried on into Asia and evolved into Homo erectus. It is more likely because it explains the puzzling absence of the characteristic H. erectus (sensu lato) teardrop-shaped Acheulian handaxes from East Asia. This problem was first noted by the US archaeologist Hallam Movius in 1948. One possible explanation is that the ancestors of the East Asian Homo erectus left Africa before the Acheulian handaxes were invented. This view is supported by the Dmanisi remains, which were found in association with stone tools of the earlier Oldowan type.

Homo georgicus is another piece in the fascinating jigsaw of human evolution, but it doesn’t “rewrite” anything. To suggest otherwise is quite simply bad science and to present a 7 year old article in Science as if it were a new discovery is even worse journalism.

It appears that I have singled out the Independent unfairly, becuse both the Times and the Guardian also ran the same story. The Times does at least make it clear the discovery happened a while ago, though why three of the UK's four quality newspapers should choose to report on the Dmanasi hominins now is a complete mystery. It also turns out that the Daily Telegraph ran the same story just under two years ago.

Incredibly even Richard Dawkins website is carrying a link - via Twitter and Fox News - to the Times article. While I am fairly certain Prof. Dawkins is not personally responsible for everything on his site, this is a little surprising! I have to say that I wish Prof. Dawkins - as the country's leading populariser of science - would devote as much time and energy to combating this kind of "bad science" as he does to opposing creationism, which anybody with a brain larger than Homo georgicus knows is utter nonsense anyway.

UPDATE 16 Sept 2009
It now turns out that David Lordkipanidze, who has headed up the Dmanisi investigation for some years, was speaking to an audience at the British Science Festival in Guildford. No new information was being presented and indeed Prof. Lordkipanidze's most recent paper on the subject appeared 2 years ago (this was the story carried by the Telegraph in September 2007). The newspapers should really have made these facts clear rather than presenting them as fresh news. Nowhere did I see the words "speaking yesterday at the British Science Festival in Guildford" which would have explained everything.

© Christopher Seddon 2009

Gabunia, L., de Lumley, M.-A., Vekua, A., Lordkipanidze, D., & de Lumley, H. (2002). Découverte d'un nouvel hominidé à Dmanissi (Transcaucasie, Géorgie). C.R. Palévol. , 1, 243–253 .
Gabunia, L., Vekua, A., Lordkipanidze, D., Swisher, C., Ferring, R., Justus, A., et al. (2000). Earliest Pleistocene Hominid Cranial Remains from Dmanisi,Republic of Georgia: Taxonomy, Geological Setting, and Age. Science , 228, 1019-1025.
Klein, R. (2005). Hominin Dispersals in the Old World. In C. Scarre, The Human Past (pp. 84-123).
Lordkipanidze, D., Jashashvili, T., Vekua, A., Ponce de Leon, M., Zollikofer, C., Rightmire, C., et al. (2007). Postcranial evidence from early Homo from Dmanisi, Georgia. Nature , 449, 305-310.
Lordkipanidze, D., Vekua, A., Ferring, R., Rightmire, G., Zollikofer, C., Ponce de León, M., et al. (2006). A Fourth Hominin Skull From Dmanisi, Georgia. The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology , 288A, 1146–1157.
Vekua, A., Lordkipanidze, D., Rightmire, P., Agusti, J., Ferring, R., Maisuradze, G., et al. (2002). A New Skull of Early Homo from Dmanisi, Georgia. Science , 297, 85-89.

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