Saturday, 10 April 2010
Australopithecus sediba: from a missing link to an evolutionary dead end
There’s no place for Australopithecus sediba in this scenario. Image courtesy of José-Manuel Benito Álvarez, Wikipedia.
The publication of a new “ape man” fossil nearly always follows a familiar formula:
1) The popular media announce the discovery of a missing link between man and apes with great fanfare.
2) Other researchers examine the find and notice that it is not the missing link that its discoverers claimed.
3) The find is forgotten.
4) A new fossil is found and the old ”missing link” is cast aside as a worthless dead end.
Usually, the popular press only reports the first stage of the story. This time, however, The Independent, published in London, gave critics plenty of space to air their views.
Many researchers said that Australopithecus sediba is an evolutionary dead end and not a missing link.
Colin Groves, a professor at the School of Archaeology and Anthropology at the Australian National University, pointed out that the South African fossils were contemporary with ”the East African Homo habilis."
Professor Groves went on to say that the “whole idea of the genus Australopithecus is actually very vague… It has been called a wastebasket category” for fossils that did no make it into the genus Homo.
The same also applies to H. habilis. To make matters more interesting, H. habilis and H. erectus are known to have been contemporaries.
Berger and colleagues acknowledged in Science that the ”ancestry of Homo and its relation to earlier australopithecines remain unresolved”. They hoped that their discovery would change this. In addition, Berger told Science Daily: ”Before this discovery, you could pretty much fit the entire record of fossils that are candidates for the origin of the genus Homo from this time period onto a small table.”
We should thus not be surprised if every new fossil (sometimes even a single tooth) makes headlines.
Berger, Lee R. & al. 2010. Australopithecus sediba: A New Species of Homo-Like Australopith from South Africa. Science 328: 5975, 195 – 204. (9 April)
Macknight, Hugh. 2010. Experts reject new human species theory. The Independent (8 April) http://www.independent.co.uk/news/science/experts-reject-new-human-species-theory-1939512.html
New Hominid Shares Traits With Homo Species: Fossil Find Sheds Light on the Transition to Homo Genus from Earlier Hominids. Science Daily. 8 April 2010.