Why do humans have much less body hair than most mammals?
Show answer & explanation
Answer: Less hair let sweat evaporate and cool the body
Less hair freed energy for building bigger muscles — Wrong. Muscle growth is not the main trade-off here. The bigger evolutionary clue is heat control.
Less hair let sweat evaporate and cool the body ✓ — Correct! One leading explanation is that less body hair let sweat evaporate more efficiently, helping early humans stay cooler during long activity in hot environments.
Less hair made humans harder for predators to spot — Wrong. Camouflage matters for some animals, but it does not explain why humans evolved powerful sweating together with reduced body hair.
More Evolution & Genetics questions
- Which of the following best describes a common change in RNA transcript length with age?
- Why do different organs in mammals show different gene activity patterns related to longevity?
- What can researchers learn about people of the same age from separate RNA-based aging clocks that estimate age from inflammation-related and metabolism-related gene activity?
- If you sort the many gene-activity changes that come with age into groups that rise and fall together, what does that grouping reveal?
- Why might aging mouse, monkey, and human cells show similar changes in the RNA they produce across different tissues?
- Why does a platypus still count as a mammal when it lays eggs and has no nipples?