The 8 yo and I were browsing the book companion to the excellent BBC series 'Walking with Cavemen' the other night. I was struck by a commentary on the peculiarity of the eternal stone tool. Modern humans appear to have gone from stone tools to quantum computers in about 30,000 years, but ancient hominids spent millions of years doing exactly the same thing. Even Neandertal seemed to create the same tools year in and year out -- though perhaps with a mechanical precision that modern humans cannot equal.
Paleontologists have tried to image what a mind would be like that showed such limited creativity. They speculate about a highly compartmentalized "intelligence", with nothing like the "general" intelligence we're alleged to have. Something, in other words, like a modern computer.
We can't yet build a non-organic sentient computer (we build millions of the organic variety every day), but we might be able to build one that would "pass" for Homo ergaster. That is, it would past the Turing-egaster test. All it needs then is a bit of evolution ...
PS. The new book costs about $35 or so. At Amazon.com, including shipping, the cost is about $9. Amazon's used book service must be having some impact on new book sales and the used book marketplace. I've not read anything about this though. We ordered a used copy.