ANT 2033 Lecture Notes - Lecture 7: Speech Production, Animal Communication, Strepsirrhini
Document Summary
As brains increase in size, the neocortex part increases disproportionately: learning, analysis and planning become more prominent. The neocortex represents: 20% of the total brain in an insectivore, 70% among monkeys and great apes, 75% in humans". Brain is a metabolically expensive tissue; requires more metabolic activity for brain growth. The brain is the third most expensive organ in the human body. Constraints to brain evolution: energetically expensive 20% at rest in humans, energy and oxygen cannot be temporarily reduced. Starvation during pregnancy = smaller babies, smaller organs, normal brains. If starvation is extreme = brain damage and cognitive deficiency: constant activity. How to grow a big brain: increase net energy. Species with more energy-dense diets have larger brains. Other individuals provide food: either directly in the form of provisioning, or indirectly by reducing the burden of reproduction (cooperative breeding) Seasonal reductions in net energy should generally selectively favor reduced brain size.
