If culture as defined by Tylor is characteristic of humans, we are confronted by a problem. As we proceed back in time, we encounter an archaeological record that suggests the absence of some of Tylor's cultural attributes and other characteristics that we assume to be exhibited by all "human" societies. According to what framework can we understand prehistoric populations that produce no observable technological inventions over thousands of generations? or that did not exchange or trade goods with other such groups? or hunt but instead lived by scavenging the carcasses of already dead animals? or decorate themselves? or that did not produce artistic images in material media? Such observations are the basis for an evolutionary perspective regarding human culture.