CEES Extra seminar: An ecometric analysis of the fossil mammal record of the Turkana Basin
By Mikael Fortelius
Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of East Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago. We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 million years ago have acted as a ‘Species Factory’, generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS member (1.87-1.53 million years ago) may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans.
Professor of Evolutionary Palaeontology, Department of Geosciences and Geography, University of Helsinki
Kristine Bonnevie Professor, Centre for Ecological and Evolutionary Synthesis (CEES), University of Oslo