Evolution, Revolution or Saltation Scenario for the Emergence of Modern Cultures?

Abstract

Crucial questions in the debate on the origin of quintessential human behaviours are whether modern cognition and associated innovations are unique to our species and whether they emerged abruptly, gradually or as the result of a discontinuous process. Three scenarios have been proposed to account for the origin of cultural modernity. The first argues that modern cognition is unique to our species and the consequence of a genetic mutation that took place approximately 50 ka in Africa among already evolved anatomically modern humans. The second posits that cultural modernity emerged gradually in Africa starting at least 200 ka in concert with the origin of our species on that continent. The third states that innovations indicative of modern cognition are not restricted to our species and appear and disappear in Africa and Eurasia between 200 and 40 ka before becoming fully consolidated. We evaluate these scenarios in the light of new evidence from Africa, Asia and Europe and explore the mechanisms that may have led to modern cultures. Such reflections will demonstrate the need for further inquiry into the relationship between climate and demographic/cultural change in order to better understand the mechanisms of cultural transmission at work in Neanderthals and early Homo sapiens populations.

Variability in the Middle Stone Age of Eastern Africa

“…If the archaeological signature of early H. sapiens varies in relation to different social and physical environments, then we should expect temporally and spatially variable patterning in the expression of those elements linked to behavioral modernity. This is consistent with the irregular temporal-spatial distribution of the archaeological signatures associated with modernity (d 'Errico 2003;d'Errico and Stringer 2011;Habgood and Franklin 2008;McBrearty and Brooks, 2000) and parallels d 'Errico and Stringer's (2011) "cultural model" of modern human behavioral origins and Conard's (2008) model for Mosaic Polycentric Modernity. By reducing emphasis on the link between biological and behavioral modernity (e.g., Hovers and Belfer-Cohen 2006;Kuhn and Hovers 2006;Lieberman and Bar-Yosef 2005) and emphasizing the situational nature of the archaeological evidence (see also Henshilwood and Marean 2003), these models are consistent with several lines of evidence, including an African biological origin for our species but a Eurasian origin for the Aurignacian (Mellars 2006a), and the presence at Neanderthal sites of some behaviors classically linked with modern humans (d 'Errico and Stringer 2011).…”

Evolutionary neuroscience of cumulative culture

“…Although any event that altered the evolutionary cost/benefit analysis of either brain expansion generally (4,8) or high-fidelity social learning specifically (2, 16) could theoretically have initiated runaway biocultural coevolution in our lineage, there is no reason to assume this feedback would be indefinitely self-sustaining once initiated, nor that that it would necessarily produce constant increase as opposed to more complex dynamics. In fact, both comparative biological evidence (4) and cultural evolutionary models (19) indicate the potential for just such interactions and dynamics and this is entirely consistent with the emerging paleoanthropological picture of multilineal, intermittent, asynchronous change over human evolution (20,21). This indication suggests a more contingent evolutionary history, likely involving multiple inflection points in response to perturbations both intrinsic (19) and extrinsic (20) to hominin behavior systems.…”

Evolution in leaps: The punctuated accumulation and loss of cultural innovations

“…Depending on the timescale studied, change in tool repertoire may appear punctuated and stepwise. Long, seemingly static, periods are interspersed between "cultural explosions," periods of sudden cultural accumulation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). Further, in some populations, there is evidence that whole suites of cultural traits, such as the ability to make tools, clothing, and fire (14)(15)(16), may be lost, defying the general trend of cultural accumulation over time (4,7,8).…”