Factors affecting Acheulean handaxe variation: Experimental insights, microevolutionary processes, and macroevolutionary outcomes

Abstract

The so-called "Acheulean" is comprised of individual knapping events undertaken by individual hominins. In other words, it is a particular component of hominin behavior that we draw out and amalgamate into a wider "pattern." The resultant phenomenon (i.e., "the Acheulean") is an entity that stretches over the space of three continents and spans a time period in excess of one million years. If such an exercise has any merit, it is because it provides a means of comparative (behavioral) analysis over these swathes of time and space. Comparative research can document, measure, and statistically assess temporo-spatial patterns of artifactual variation, and so test hypotheses regarding the character of that variation. However, comparative research alone is not sufficient to fully understand this archaeological legacy. Here, we review and synthesize recent experimental work that we have undertaken, which has specifically investigated some of the factors potentially responsible for the generation and constraining of variation within the Acheulean techno-complex. We examine issues of raw material, copying errors, and their relationship to mechanisms of social learning. Understanding these microevolutionary factors via experiments, we contend, is essential in order to reach a secure understanding of the macroscale phenomenon typically referred to as the "Acheulean."

Investigating interrelationships between Lower Palaeolithic stone tool effectiveness and tool user biometric variation: implications for technological and evolutionary changes

“…Thus, the onset of the Acheulean was likely not only dependent upon relevant cognitive abilities (e.g. Stout et al, 2008;Faisal et al, 2010;Stout, 2011), and social learning factors (Lycett et al, 2016), but physical factors may also additionally have curtailed the use and adoption of handaxe technology up until a specific point in human evolutionary history.…”

Differences in Manufacturing Traditions and Assemblage-Level Patterns: the Origins of Cultural Differences in Archaeological Data

“…However, it is also worth reemphasizing that both selective biases and drift (i.e., stochastic processes) will have the capacity to influence and instigate such long-term change in such variations as a direct result of their proximate behavioral basis Eerkens and Lipo 2007;Hamilton and Buchanan 2009;Lycett 2008;Lycett and von CramonTaubadel 2015;Lyman et al 2009;Mesoudi 2011;Neiman 1995;Rogers et al 2009;Shennan 2000Shennan , 2011. Indeed, the experiment demonstrates the capacity for relatively minor behavioral differences to mediate the potential "heritability" of artifacts in cultural systems, which is a specific quantitative property possessed by artifact populations that can be conceived of as a ratio of the within-assemblage artifactual variation to the within-population behavioral variation of their makers that is directly influencing artifactual variability (Lycett 2016;Lycett et al 2016). As shown elsewhere, this ratio is important since it is ultimately this variable that determines how quickly an artifactual tradition may respond to cultural evolutionary pressures of selection or drift in absolute terms (Lycett 2016;Lycett et al 2016).…”

“…Indeed, the experiment demonstrates the capacity for relatively minor behavioral differences to mediate the potential "heritability" of artifacts in cultural systems, which is a specific quantitative property possessed by artifact populations that can be conceived of as a ratio of the within-assemblage artifactual variation to the within-population behavioral variation of their makers that is directly influencing artifactual variability (Lycett 2016;Lycett et al 2016). As shown elsewhere, this ratio is important since it is ultimately this variable that determines how quickly an artifactual tradition may respond to cultural evolutionary pressures of selection or drift in absolute terms (Lycett 2016;Lycett et al 2016). Our experiments highlight how even subtle behavioral differences between individual artifact manufacturers can quantifiably influence this variable as a result of their effects at the artifactual level.…”

“…Artifactual variation per se is not enough-that variation has to have a behavioral basis. In other words, the source of such variation has to be transmittable (i.e., culturally "learnable") by means of social interaction ("social learning") if it is to be of relevance in cultural evolutionary systems and subsequently have any implication for inferring behavioral factors via measurement of artifactual variation within such a framework (Lycett and von Cramon-Taubadel, 2015;Lycett 2016;Lycett et al 2016). …”

“…Elsewhere, we have argued that in regard to the study of cultural evolutionary processes, simple experiments that replicate certain aspects of artifactual form (e.g., their size and/or shape) make a particularly useful subject of study for similar reasons Schillinger et al 2014a). Hence, similarly to the use of such experiments in evolutionary biology, the examination of "model artifacts" in controlled laboratory settings can help shed light on fundamental microevolutionary process that are directly relevant to issues that must be considered when examining wide-scale and long-term patterns in the archaeological record (Eerkens 2000;Kempe et al 2012;Lycett et al 2016;Mesoudi and O'Brien 2008;Schillinger et al 2014aSchillinger et al , 2014b.…”