Demography and the evolution of genetic and cultural variation

• Main Author: Powell, A. T.
• Published: University College London (University of London) 2011
• Subjects: 576.5
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.565251

This thesis addresses how demographic processes affect both genetic and cultural variation. Drawing on theory and techniques from both gene-culture coevolution and population genetics, and using both genetic and archaeological data, I present a number of projects covering a wide range of questions on the evolutionary history of our species. Chapter 2 develops a simulation model of the gene-culture coevolution of lactase persistence and dairying in Neolithic Europe. Using approximate Bayesian computation (ABC) to integrate modern genetic and archaeological data, the results demonstrate that this coevolutionary process began —7,500 years ago in central Europe. The inferred origin is closely associated with the emergence of the Linearbandkeramik (LBK), an early cattle-based dairying culture. Chapter 3 extends a previous cultural evolutionary model to show that heterogeneity in subpopulation density causes spatial structuring of culturally inherited skill accumulation. Genetic estimates of regional effective population density demonstrate that the appearance of modern human behaviour during the Late Pleistocene can be explained by demographic factors. Chapter 4 reviews the application of the neutral model in archaeological and other cultural contexts, and develops a novel statistical approach to test for deviation from neutrality. Results show that surprisingly high levels of non-neutrality, in the form of frequency- dependent copying, can go undetected. Chapter 5 develops a novel neutral model of cultural evolution, relaxing some previous common assumptions outlined in Chapter 4. The model allows accurate estimation of population parameters from minimal archaeological data, and is applied to a decorated pottery dataset from the LBK settlements of southwest Germany. Chapter 6 outlines the utility of the coalescent model of population genetics in inferring potentially complex demographic histories using both modern and ancient DNA samples. I provide two examples of my work from collaborative projects on the domestication of Near Eastern cattle and the demographic history of the Hispaniolan hutia.