HONORS 232 Lecture Notes - Lecture 5: Risk Aversion, Bipedalism, Alloparenting
Document Summary
Current and future reproduction: organisms that reproduce slower tend to have bigger brains, longer life spans, small litters, and larger body sizes, what are the benefits of waiting to reproducing? i. Do they need time to 1) grow big brains and 2) learn skills: ecological risk aversion hypothesis: growth rates, age at maturity, reproductive rates vary inversely with juvenile starvation rates i. ii. If juvenile starvation risk is high the age of maturity is slow and they will reproduce later. Example: as fruit is more dispersed and harder to predict, fruit eaters mature more slowly iii. iv. Our big brains represent capital which allowed us to evolve to get high quality resources: scaling brain size i. How do we afford our brains: of our calories burned are for the brain very metabolically costly, expensive tissue hypothesis: the brain is 2% of body weight, but consumes 18% of energy.
