| climbing to reach females: romeo should be small. | the race for reaching mates by the time they are receptive, or sexual selection by scramble competition, has received little attention. we argue that smaller males are favored in species in which the male must climb to reach females located in high habitat patches. this new explanation we term the "gravity hypothesis" of sexual size dimorphism (ssd). we show that a simple biomechanical model of animal movement predicts that: (1) selection should favor a comparatively smaller size in the searchin ... | 2002 | 11926508 |