Sexual Selection in Human Evolution - Controversies

Controversies

The role of sexual selection in human evolution has been considered controversial from the moment of publication of Darwin's book on sexual selection (1871). Among his vocal critics were some of Darwin's supporters (for example, Alfred Wallace). Darwin was accused of looking to the evolution of early human ancestors through the moral codes of the 19th century Victorian society. Joan Roughgarden, citing many elements of sexual behavior in animals and humans, that cannot be explained by the sexual-selection model, suggested that the function of sex in human evolution was primarily social. Joseph Jordania recently suggested that in explaining such human morphological and behavioral characteristics as singing, dancing, body painting, wearing of clothes, Darwin (and proponents of sexual selection) totally neglected another important evolutionary force, intimidation of predators and competitors with the ritualized forms of warning display. Warning display uses virtually the same arsenal of visual, audio, olfactory and behavioral features as sexual selection. According to the principle of aposematism (warning display), in order to avoid costly physical violence and to replace violence with the ritualized forms of display, many animal species (including humans) use different forms of warning display: visual signals (contrastive body colors, eyespots, body ornaments, threat display and various postures to look bigger), audio signals (hissing, growling, group vocalizations, drumming on external objects), olfactory signals (producing strong body odors, particularly when excited or scared), behavioral signals (demonstratively slow walking, aggregation in large groups, aggressive display behavior against predators and conspecific competitors). According to Jordania, most of these warning displays were incorrectly attributed to the forces of sexual selection. Jordana proposed an aposematic model of human evolution, where most of the human morphological and behavioral features that had been considered by Darwin as the result of sexual selection, via female choice, are explained by the aposematic (intimidating) display. Rather than sexual selection, the alternate concept is self-selection and rejection of the weak, as survival of the loudest.