Human Brain and Race Notes

Afarensis began to develop openings in the skull

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Unformatted text preview: • • o Dietary Change Hypothesis Hominins predating Homo erectus ate aquatic animals (turtles, crocodiles, fish) – faunal remains dated to 1.95 Mya • Such foods provide nutrients needed in human brain growth o Stone tool manufacture and use hypothesis But stone tools were being manufactured and used by non ­Homo species as early as 2.5 Mya Which came first? o Climate Change Hypothesis o Social Behavior Hypothesis The Radiator Hypothesis o In hot environment, brain temperature may be the one biggest limit on survival (and human brains generate energy) o A. afarensis began to develop openings in the skull (emissary foramina) through which blood could flow out to cool the brain o Brain temperature was constraint; ‘radiator’ released this constraint o Cranial radiators (networks of veins removing heat form brain) appeared in late gracile Australopithecus, but not Paranthropus spp. (robust forms) Is considered a prime releaser of the thermal constraint, but is not necessarily the prime mover of human brain evolution Diet and Brain: What were we ‘meant’ to eat? ‘Expensive Tissue’ Hypothesis o Large brain...
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This note was uploaded on 04/24/2013 for the course NS 201 taught by Professor Busher during the Fall '08 term at BU.

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