ABSTRACT

Dimorphism grows in proportion to the degree of polygamy for fairly self-evident reasons. The species of apes to which humans are most closely related are decidedly polygamous, and likewise highly dimorphic. An attempt to discover an approximate date for the beginnings of human monogamy can therefore rely on comparisons of the bodies of males and females in the epochs that witnessed the passage from apes to human beings. The most complete of the small number of Australopithecus skeletons which have been found until now is known as Lucy and is famous even among laymen. South-east Africa, where Lucy was found, has also furnished many number of individual bones, both male and female, from much the same epoch. The males' perfection of their profound relationship with blood was also accompanied by a strange coincidence: evolution saw fit, at much the same time, to make human menstrual blood much more abundant and conspicuous than it is among animals.