Do species factories exist? Detecting exceptional patterns of evolution in the mammalian fossil record

Abstract

A species factory refers to the source that gives rise to an exceptionally large number of species. However, what is it exactly: a place, a time or a combination of places, times and environmental conditions, remains unclear. Here we search for species factories computationally, for which we develop statistical approaches to detect origination, extinction and sorting hotspots in space and time in the fossil record. Using data on European Late Cenozoic mammals, we analyse where, how and how often species factories occur, and how they potentially relate to the dynamics of environmental conditions. We find that in the Early Miocene origination hotspots tend to be located in areas with relatively low estimated net primary productivity. Our pilot study shows that species first occurring in origination hotspots tend to have a longer average longevity and a larger geographical range than other species, thus emphasizing the evolutionary importance of the species factories.

Plio-Pleistocene African megaherbivore losses associated with community biomass restructuring

“…Today, interactions between mammalian herbivores and their physical environments are largely mediated through the plants they consume, such that large mammal herbivore biomass is strongly positively correlated with net primary productivity (NPP) (27). Major decreases in NPP since the Late Miocene have previously been recorded in both North America and Europe (28,29), suggesting a global pattern. Such NPP losses could have considerably diminished the total biomass (carrying capacity) of large mammal communities, thereby reducing diversity and causing megafaunal extinctions following the guillotine model.…”