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Unformatted text preview: t half of the Pleistocene. This helps increased behavior adaptability. 25 The Pleistocene climate deteriorations is correlated with increase in brain size in many mammalian lineages beside our own. All other thing being equal selection would favor small brains for brains are costly (human brain: 16% of basal metabolism, average mammal 3%).
Other brain costs: difficulties at birth; long learning period; greater vulnerability to head trauma, … If brains got bigger it must have been for some good purposes.
26 If complex culture is a highly advantageous means of adapting to Pleistocene, why it is so rare?
Only fairy sizable populations can sustain complex, culturally evolved artifacts and behaviors.
E.g.: the complexity of tool kit began to deteriorate when Tasmania got disconnected to the mainland. Yet the Tasmania population was not tiny. When Europeans arrived it numbered at around 4 thousands). Surprisingly large population is required or the sustainability of tools consisting of many hundreds complex items. (cf.: division of linguistic labor).
27 Many preadaptations must have been in place for culture to develop and evolve. Like winning the lottery …
Upright posture and hands did not by themselves set of a rush to complex culture (the brain of first hominid, 4 millions years ago, is not bigger than ape’s one.
The tools tradition was not transmitted by imitation, but rather maintained by other learning mechanisms similar to the one of present apes.
28 Home erectus (1 million to 100,000 yeas ago) have larger brain and bodies than the bipedal a...
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This document was uploaded on 10/26/2011 for the course PHIL 3501 at Carleton CA.
- Fall '07