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Selected Books by Edmund Blair Bolles

  • Galileo's Commandment: 2500 Years of Great Science Writing
  • The Ice Finders: How a Poet, a Professor, and a Politician Discovered the Ice Age
  • Einstein Defiant: Genius vs Genius in the Quantum Revolution

« A Lifetime of Wondering | Main | The Minimum Requirements for an Acceptable Theory »

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Raymond Weitzman

I'm puzzled by your last sentence. What suggestions are you referring to? The paleoanthropologists did actually find the anatomical features they describe in A. sediba. As far as I know, this hasn't been disputed yet. In the news articles I have read, some scholars suggested that A. sediba was a transitional species between the genus's Australopithecus and Homo. One scholar mentioned the possibility that sediba was an ancestor of H. habilis or H. rudolfensis or H. erectus.I didn't find in my sources the suggestion that sediba was a hybrid. It is, of course, a possibility, if it can be shown that Homo and Australopithecus co-inhabited the same territory at the same time.
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BLOGGER: What suggestions am I referring to? “…suggests that the brain was being rewired … suggests a double story …suggest both tree climbing and precision grip …suggests a human like arched foot…”

The anatomical features are there. The question is whether they are part of the human lineage.

The standard story has been that around 2.7 mya the genus Homo appeared. We may be descended from H. habilis or rudolfensis or some other species of early Homo. The two key features suggesting that they are ancestral is that their brain began to get bigger and they began making tools to make other tools, the Oldowan technology of flakes made from hammerstones.

An alternate story might be that we are descended from Australopithecus sediba instead. How could that be? Well, the early Homo species might be misidentified and we have no relation to them, but that is a bit of a puzzle because their brain was getting bigger and they were using tools that are clear forerunners of the Homo erectus Acheulian technology. There is speculation that sediba was a tool user too, but no tools have been found. Another possibility is that sediba and Homo crossbred, keeping the big brains of Homo and the sediba rewiring, and bringing Oldowan technology. Yet another possibility is that sediba is entirely off the human lineage. We don’t yet know which answer is correct, but the latest news has the enjoyable feature of stirring things up.

Raymond Weitzman

But the "standard story" does not seem to be a credible one. At least it is not backed up by good evidence. Pickering, et. al. in the current issue of Science suggests that the evidence of Homo before 1.9Ma has not been unequivocally demonstrated.

You are certainly right about finding A. sediba has really stirred things up and probably also adds confusion to trying to trace the origins of speech.

www.google.com/accounts/o8/id?id=AItOawkyQS5sJI490gt15Sj58MbwLOMW2LgSwoY

I have recently finished reading Chris Stringer's new book "The Origin of Our Species" and posted a review on my blog "www.Trapped-by-the-Box.blogspot.com". A one of the world experts in the field Chris clearly knew of the South African developments in advance but could only hit at possible developments to come. As someone who is very interested in the analysis and communication of information his book clearly indicates the current problem. Trying to recreate the human family tree is like a giant jigsaw puzzle where 99.9999% of the pieces are missing. While an enormous amount has been discovered, particularly helped by modern scientific techniques, there are still major surprises such as the Denisovans and these latest South African discoveries.

Basically we still seem to be at the stage of still discovering new areas which need exploring. For instance just because one hominid has a bigger brain does not mean he was an ancestor as several branches may have been under the same evolutionary pressure to develop their brain in different parts of Africa, and once you throw in the possibility of different groups interbreeding at different times over the last 4 million years or so the complexities are huge.

As a scientist I consider the research is at a very exciting time but every theory must be looked at critically and expect to be radically modified. In terms of language evolution I am wondering if the preservation of these South African remains can tell us anything about the development of the larynx.

Chris Reynolds

Raymond Weitzman

The August issue of National Geographic has an article on A. sediba with a nice chart called Murky Birth trying to trace the ancestry of H. sapiens. As Chris says above it is really a giant jigsaw puzzle with most of the pieces missing, just like trying to recognize a photo with a large number of pixels missing. But we certainly don't need all the pixels to recognize the photo. I wonder how many pieces of the jigsaw puzzle do we need to get a fairly clear idea of our lineage.

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