Changing Views on Australopithecus afarensis

The other day I stumbled across an interesting article by Kimbel and Delezene, published last year in the Yearbook of Physical Anthropology, called ‘‘Lucy’’ Redux: A Review of Research on Australopithecus afarensis. I’m just now getting around to reading it and one paragraph jumped out at me:

It is all too easy to forget that paleoanthropology was very different in 1973, when the first Hadar fossils were recovered, than it is in
2009, and what may appear today to be a ‘‘status quo’’ stance on A. afarensis developed out of a period of significant changes in both data and theoretical outlook that propelled paleoanthropology rapidly forward as a science. We think this is particularly important for students to appreciate, especially as their near-total dependence on the digital domain for access to scholarly information has kept them out of the libraries, where much of the ‘‘older’’ literature— and the scientific world it conveys—remains in print form.

Brother, ain’t that the truth! Consider this quote from Birdsell’s Human Evolution (3rd ed. – pg. 248):

Johanson and White further claim the A. africahus (sic) is ancestral to A. africanus and later, progressive forms of Homo. From their view of the pongid traits present, they hypothesize a late split between the hominids and the pongids, say 5 to 8 million years ago. These ideas are controversial and need more supporting evidence before they can be totally accepted.

Earlier in the book, in a box titled Non-Darwinian Evolution and the Molecular Clock Birdsell had this to say:

From the point of view of human evolution, one of the most important of Sarich’s predictions says that chimpanzees and man should have a common ancestor as recently as 4 to 8 million years ago. Sarich’s method does indicate a basis for this view, but the fossil record of the ancestry of the hominoids is not in total support of this idea. Admittedly, a very important gap exists in the record between the hominoid radiations of the Miocene and the appearance of Homo, but the time interval suggested by Sarich seems very short. He even suggests that if fossils are discovered that seem to relate to human evolution but are earlier than his time schedule, they should be ignored. The recovery of evidence that Australopithecus afarensis walked bipedally and completely upright at Laetolil nearly 4 million years ago makes it difficult to believe that this hominid had a common ancestor with the chimpanzee in its immediate past, or even as far back as 8 million years ago.

It was a really different world back then…

Update 1: I forgot to mention that the 3rd edition of Birdsell’s book was published in 1981. It was the textbook my teacher used in the first physical anthropology class I ever took. For its time it was actually pretty good.

The next edition of the Four Stone Hearth will be at Archive Fire on 12/08. Follow the link to get submission information. You may also submit posts to me at the email address on the “about” tab.

I am also looking for hosts for future editions, hosts are needed for 01/05, 01/19, and 02/02.

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