L8 - Boundaries of Childhood

Question 1

For prolonged childhood to evolve…

Answer 1

costs of delayed maturity must be outweighed by new benefits

Question 2

The Costs of Delayed Maturity

Answer 2

1. decreases number of potential reproductive attempts across lifespan
2. late reproduction increases generation time - decreases long term fitness
3. late reproduction increases risk of death before successful reproduction

Question 3

The Benefits of Delayed Maturity

Answer 3

-investment in adult reproductive potential (growing to larger size, physical strength, cognitive abilities, learning skills)

Question 4

Why do girls typically mature earlier than boys?

Answer 4

• costs of delayed maturity may be higher in females (menopause truncates female reproductive phase)
• benefits of delayed maturity may be higher for males (skill development important for mating competition - and males may benefit from avoiding intrasexual competition)

Question 5

Why is age of menarche earlier than past centuries?

Answer 5

• perhaps better nutrition & energy balance
• father absence? Might signal high mortality risk, favoring accelerated life history. OR reduction in nutrition?
• mechanism for incest avoidance/response to new males in environment?