This means that sexual dimorphism—the physical differences between the males and females of a species—is increasing for humans, all thanks to improved standards of living over time.

They also have straighter, thinner tusks, more rounded ears and differently shaped skulls. Both elephant species exhibit sexual dimorphism, where males are larger than females, with wider-set tusks, ...

[b] Several species exhibit sexual dimorphism. They have streamlined bodies and four limbs that are modified into flippers.

Sexual Dimorphism in the Animal Kingdom; a Theory of the Evolution of Secondary Sexual Characters. By J. T. Cunningham Pp. xi + 317; with 32 illustrations. (London: Adam and Charles Black ...