Exploring Human Origins

Abstract

[FIRST PARAGRAPH] As a social species, humans have unrivaled abilities to engage in sym- bolic thought and language and in moral, cooperative, and altruistic behaviors. Art, literature, music, mathematics, and science flourish only in human societies. Cultures and adaptive learned behaviors are socially rather than genetically transmitted from generation to gener- ation and evolve in response to technological innovations. Under- standably, humanists and social scientists are not captivated by the idea, increasingly prevalent in popular culture, that the DNA sequence of the human genome contains a book of instructions that defines being human. This DNA reductionist view of being human, with its corollary that genes are much more important than environments in dictating how different individuals act, is far too simplistic. A more defensible view is that during humankind’s evolutionary history, genic changes occurred in ancestral genomes that were positively selected to help shape the distinctive human phenotype. This view complements rather than contradicts the view that our social envi- ronment guides how we act. Perhaps the major trend in humankind’s evolutionary history has been the selection of genomes that gave their bearers the brain power to use learned, culturally transmitted behaviors to cope successfully with an increasing range of external challenges. Thus, paradoxically, because of humankind’s genetic evolution, the future of the human species now heavily depends on its further cultural-social evolution rather than its further biological evolution.