Mark Thomas is Professor of Evolutionary Genetics at University College London and works mainly on biological and cultural aspects of human evolution. He uses computer simulation and statistical modelling to make inferences from genetic data – including ancient DNA – and archaeological information, on processes such as past migrations and dispersals, natural selection – particularly in response to changes in diet and infectious disease loads – and how demography shapes genetic and cultural evolution.
Palaeolithic Diets and the Evolution of Lactase Persistence
In recent years knowledge of human evolution has influenced popular views on the relationship between diet and health. One such view – often attributed to the PaleoDiet™ community – is that diets similar to those of our Palaeolithic ancestors are likely to yield considerable health benefits. However, while it is true that – to a first order of approximation – our physiology should be optimised to the diets we have experienced during our evolution, current knowledge of what those diets were remains very limited. In addition, we now know that human populations have adapted by natural selection to changes in diet since the advent of farming some 10,000 years ago. The most dramatic example of this is the evolution of lactase persistence, which allows consumption of large quantities of fresh milk without the adverse effects of lactose malabsorption (often called lactose intolerance). Using new data on hunter-gatherer and Palaeolithic diets, I will show that consumption of dairy is compatible with the view that ancestral diets are beneficial.