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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

« Chimp Generosity | Main | Babel's Dawn in Stores »


Raymond Weitzman

There can be no doubt that something interesting started happening to human (Genus Homo) brains about 2.5 to 2.75 million years ago (or earlier) and we see correspondingly that something was also happening to how these early humans were behaving. Around 2.5 million years ago is the earliest evidence for stone-tool making and the controlled use of fire. This suggests that humans were gaining more control over their environment. On the other hand, other hominidae brains, like the chimpanzee, seem to have remained more or less the same—at least in size—and we have no evidence to suggest that they were gaining a better control over their environment. By implication, this does suggest that along with bigger brains humans were gaining more control over each other as a way of gaining more control over their environment (cooperation?) and strengthening the chance for group survival. How was all this being done? As Blair suggests, some kind of incipient language may well be the mechanism.

Brain size changes are only suggestive of the qualitative changes that were taking place in humans. From what I understand, most of the changes seem to involve the cerebral cortex and the cerebral cortex seems to be strongly correlated our capacity for speech. Some have referred to speech as one of the means we have to express thought. This seems to imply that thought pre-existed speech. So before there was speech, humans must have been doing a lot of thinking. But what were they thinking about and how was this thinking manifested? Also was this thinking on the same order as that of other hominidaes or was it of a higher magnitude and how shall we ever know? As an aside, I get the impression that Chomsky’s conception of the language module was an innovation first affecting thought.

Another interesting point is that communication does not necessarily require a large brain, much less a cerebral cortex. The nervous system of the bee only contains about 960,000 neurons (compared to the 100,000,000,000 of the human nervous system, including 11,000,000 in the cortex). And the bee has no cortex! Yet it has a fairly sophisticated, albeit limited, system of communication. The neurons involved in the bee’s system of communication must be sufficient to allow volitional control over the parts of the body required for doing its communicative dance, but there also must also be neurons involved in the “listener” bee to recognize what all those gyrations mean. But are these specialized neurons or neuron configurations? Or do they perform many other kinds of functions as well?

Anyway, I just got word from Amazon that Babel’s Dawn will be released on August 14th! Great news.
BLOGGER: There was also a great environmental shift 2.75 million years ago. African woodland gave way to grassland,, a very spooky and difficult environment. Food is hard to find, predators are hard to avoid and impossible to outrun. A revolutionary adaptation was required if Homo was to survive in the new setting. It was the end of the upright ape.

Raymond Weitzman

Bipedalism in Homo has been claimed by some scholars to have been the result of the environmental change from forest to grassland. This, however, has been disputed by others. In fact, I think there is some evidence to suggest that bipedalism began before the environmental change. It is also interesting to note that chimpanzees can be found in a grassland environment, yet they didn't develop bipedalism. Was that because the food sources were different for Pan and Homo? Also, was bipedalism a factor in brain development? If so, what part of the brain was most influenced by bipedalism? Certainly the cerebellum must have been influenced, and perhaps the visual centers of cortex. Of course bipedalism influenced the development of the vocal tract and the positioning of the larynx.
BLOGGER: Bipedalism is much older than the savanna.

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