No Archaic/Modern Divide; or, Behavioural Variability in Premodern Humans

February 26, 2011

From American Scientist:

For decades, archeologists have believed that modern behaviors emerged among Homo sapiens tens of thousands of years after our species first evolved. Archaeologists disagreed over whether this process was gradual or swift, but they assumed that Homo sapiens once lived who were very different from us. These people were not “behaviorally modern,” meaning they did not routinely use art, symbols and rituals; they did not systematically collect small animals, fish, shellfish and other difficult-to-procure foods; they did not use complex technologies: Traps, nets, projectile weapons and watercraft were unknown to them.
Premodern humans—often described as “archaic Homo sapiens”—were thought to have lived in small, vulnerable groups of closely related individuals. They were believed to have been equipped only with simple tools and were likely heavily dependent on hunting large game. Individuals in such groups would have been much less insulated from environmental stresses than are modern humans. In Thomas Hobbes’s words, their lives were “solitary, nasty, brutish and short.” If you need a mental image here, close your eyes and conjure a picture of a stereotypical caveman. But archaeological evidence now shows that some of the behaviors associated with modern humans, most importantly our capacity for wide behavioral variability, actually did occur among people who lived very long ago, particularly in Africa. And a conviction is growing among some archaeologists that there was no sweeping transformation to “behavioral modernity” in our species’ recent past.

As Misia Landau argued nearly a quarter of a century ago in the essay “Human Evolution as Narrative” (American Scientist, May–June 1984), prescientific traditions of narrative explanation long encouraged scientists to envision key changes in human evolution as holistic transformations. The idea of an archaic-to-modern human transition in Homo sapiens arises, in part, from this narrative tradition. All this makes for a satisfying story, but it is not a realistic framework for understanding the actual, complex and contingent course of human evolution. Most evolutionary changes are relatively minor things whose consequences play out incrementally over thousands of generations.

In order to better understand human prehistory, I recommend another approach, one that focuses on behavioral variability. This trait, easily observed among recent humans, is becoming more apparent in the archaeological record for early Homo sapiens. Prehistoric people lived in different ways in different places at different times. We must seek out and explain those differences, for, in evolution, only differences matter. Thinking about prehistoric human behavioral variability in terms of various adaptive strategies offers an attractive way to explain these differences. But first, we need to discard an incorrect and outdated idea about human evolution, the belief that prehistoric Homo sapiens can be divided into “archaic” and “modern” humans.