sentences:  It was shown that males with desirable traits (large body size, high aggression, and long courtship dances) had longer copulation duration than males with undesirable traits.In "A. keyserlingi" and "Nephila edulis" females allow longer copulation duration and a second copulation for smaller males.The gravity hypothesis suggests that some species of spiders may favor smaller body sizes because they enable them to climb up plants more efficiently and find a mate faster.