Climate and evolution: implications of some extinction patterns in African and European Machairodontine Cats of the Plio-Pleistocene

Resumen

Recent discussions of correlations between global climatic change and evolution of the African Plio-Pleistocene biota have revealed apparent discrepancies between the timing and significance of events recorded in different data sets. The most notable differences have occurred in relation to a major shift in the ratio of marine oxygen isotopes by 2.5 myr and claims for a causally related transition in the biota. Vegetational changes recorded in palaeosol stable isotope values suggest that the major increase in more open vegetation occurs later ∼1.7 myr. We investigate the problem with particular reference to events at 1.7 myr and the African extinctions of machairodont cats that take place in their aftermath, since extinctions of such eurytopic taxa are likely to mark significant changes in conditions. We compare the pattern of such extinctions with those of similar or identical taxa in Eurasia and the New World, and suggest that a major environmental change is clearly indicated in each case. It is likely that the African vegetational changes recorded ∼1.7 myr represent a terrestrial response to global climatic changes recorded in marine core records ∼1.9 myr.