1) Prof. Daryl Codron

The central interior of southern Africa encompasses three major biomes – the grassland, Karoo, and Kalahari savanna, all of which today are considered semi-arid to arid habitats. Conditions of the mid-late Pleistocene were quite different, with much of the region experiencing higher, and often year-round, rainfall, and surface water being abundantly available in the form of perennial lakes and wetlands. Through this period, the mammalian fauna experienced two major turnover events, as woodlands gave way to treeless, open grasslands, ending the Cornelian Land Mammal Age (CLMA), and aridification events of the terminal Pleistocene and early Holocene ending the Florisian LMA. Stable isotope evidence from the rich fossil record of the region show a demonstrable shift in the diet and habitat niches of resident mammalian herbivore species, from mixed woodland/grassland utilization in the CLMA, to a wider diversity of diet niches, including specialized browsers, specialized grazers, and mixed-feeders in the FLMA, to almost only specialists in the less speciose modern LMA. Model simulations support the notion that these changes reflect a process of self-organized similarity, a response whereby species minimize fitness-reducing effects of interspecific competition by ‘clustering’ in multispecies groups at intervals within the available niche space. These results demonstrate not only the impacts of reductions in primary productivity on biodiversity, but also how species interactions modulate the effects of environmental change on the structure and diversity of ecological communities.