1. Both biologists are correct. One is discussing proximate causes for behavior and the other is discussing ultimate causes for behavior. Increased aggressiveness will lead to increased access to females, but increased testosterone will cause increased

1. Both biologists are correct. One is discussing proximate causes for behavior and the other is discussing ultimate causes for behavior. Increased aggressiveness will lead to increased access to females as a result of higher levels of testosterone. Males with the genes to produce increased testosterone during the breeding season will have greater fitness, due to their increased access to females, and therefore genes for increased testosterone will have increased fitness.