Social Philosophy

Feasts and Famines: the African Rift Valley, climate rollercoaster and human evolution

Dr Susanne Schultz
30th September 2015, 8:00pm

The East African Rift Valley is undoubtedly the evolutionary cradle of hominins (the group consisting of modern humans, extinct human species and all our immediate ancestors). Far more hominin species’ First Appearance Dates (FAD) have been recorded in this region than anywhere else. It has been recently argued that this reflects the unique tectonic and climatic forces in the East African Rift Valley, which resulted in dramatic climate shifts over the Quaternary, in which periods of high rainfall, coupled with the appearance of large lake basins resulted in periods of high productivity. These periods were followed by prolonged drought (or reduced rainfall) and the subsequent contraction and disappearance of the freshwater lakes. These climate shifts are contemporary with hominin speciation and extinction events, which has led to the development of the Pulsed Climate Variability Hypothesis, which argues that climate change in East Africa played a vital role in stimulating human evolution. However, to further evidence the theory, the large climate shifts should also impact on other vertebrates, and specifically, large mammals in the region. Dr Schultz will discuss the regional events that led up to a profound ecological change associated with 1.8-2 million years ago and the evolutionary pressures that might have been exerted on the contemporary hominins. Finally, she will contrast the Pulsed Climate Variability Hypothesis with other hypotheses focusing on how paleoclimate impacted on human evolution.

About the Speaker

Dr Susanne Shultz is a Royal Society University Research Fellow in the Faculty of Life Sciences at the University of Manchester. Her research focuses on behavioural evolution, especially with regard to the understanding of the emergence of human and animal societies. She has also worked with Professor Mark Maslin who first introduced the idea of the Pulsed Climate Variability Hypothesis in 2009 with Professor Martin Trauth. Professor Maslin has also worked with another of our speakers, Dr Simon Lewis, on ‘Defining the Anthropocene’. Attendees of this lecture may also be interested in Dr Lewis’ lecture for the Science & Technology Section on Thursday 22nd October.