A simulations approach to the genetic and cultural prehistory of humans

A multidisciplinary approach to history has become important. This thesis explores two problems of human prehistory. Both problems are approached using realistic simulations of models of human evolution. Simulation models can supply theoretical answers to problems in population biology which are out of reach for mathematical techniques. Even if there is an analytical technique that may answer the problem, this may not be achievable before simulation. The problems dealt with in this thesis do not have an analytical solution so far, because of the complexity of the models being simulated. Simulation of complex phenomena (such as human settlement history) can sort out essential variables or discover unexpected conclusions. Moreover, many of the mathematical theories of population biology are themselves approximate or highly oversimplified, and simulations help in showing their range of applicability.;In this thesis, we first look at a dynamic simulation model called the serial founder effect that explains the geographic patterns of genetic diversity from a sample of the world's native populations. The serial founder effect model reveals the signature of human migrations out of Africa 50,000-60,000 years ago in the human genome, and deviations from it can also be explained by later migrations from the known demographic histories of the populations. We then extend the serial founder effect model to make it more realistic and try to estimate the various parameters of human migrations by matching the observed patterns with the predictions of the model for different sets of parameters. Our results show that the serial founder effect may also apply to the recent expansion of other cosmopolitan invasive species with appropriate refinements to the parameters.;Finally, we explore how cultural choices could have influenced human migrations by focusing on one important cultural choice -- egalitarianism vs hierarchy in society. Through multi-agent simulations on island populations, we show that egalitarian societies have higher demographic stability, fewer population crashes and are less likely to go extinct. We explore the possibility that the demographic instability caused by socioeconomic hierarchy could have driven human migrations and conflict in times of population crashes, and thereby to the spread of hierarchy by demic diffusion.