Evolution of Neogene Mammals in Eurasia: Environmental Forcing and Biotic Interactions

Abstract

The relative weights of physical forcing and biotic interaction as drivers of evolutionary change have been debated in evolutionary theory. The recent finding that species, genera, clades, and chronofaunas all appear to exhibit a symmetrical pattern of waxing and waning lends support to the view that biotic interactions shape the history of life. Yet, there is similarly abundant evidence that these primary units of biological evolution arise and wane in coincidence with major climatic change. We review these patterns and the process-level explanations offered for them. We also propose a tentative synthesis, characterized by interdependence between physical forcing and biotic interactions. We suggest that species with evolutionary novelties arise predominantly in “species factories” that develop under harsh environmental conditions, under dominant physical forcing, whereas exceptionally mild environments give rise to “oases in the desert,” characterized by strong competition and survival of relics.

Climate-vegetation modelling and fossil plant data suggest low atmospheric CO<sub>2</sub> in the late Miocene

“…These conclusions are also supported by fossil mammal data (e.g. Fortelius et al, 2014). In the 280 ppm run a mix of evergreen forests, grasslands and dry savannas covers most of the Mediterranean and areas up to the Caucasus, with varying degrees of openness (Figs.…”

“…Mosbrugger et al, 2005) and landscapes in North America opened (Eronen et al, 2012). In many regions, it was still characterised by warm and humid climatic conditions compared to today Utescher et al, 2011;Eronen et al, 2012;Fortelius et al, 2014). The global continental configuration in the Miocene was generally comparable to the modern situation with some small differences (e.g.…”

Twenty-million-year relationship between mammalian diversity and primary productivity

“…2 A-H). Miocene γ diversity peaked earlier in North America (stratigraphic stage Burdigalian) than in Europe (Tortonian), a difference that has been linked to earlier drying and cooling in North America (14,21,22). In our terrestrial plant datasets, North America shows consistently lower NPP than Europe in the Miocene but not in the Early Pliocene ( Fig.…”

“…Although temporal changes in terrestrial fossil diversity have been linked to changing productivity and temperature (12)(13)(14), the few quantitative analyses to date have been performed at highly disparate spatial scales, either global to continental or for single fossil locations (15)(16)(17). The evidence for terrestrial diversity-climate relationships from these studies is equivocal, calling into question the universality of the diversity-productivity relationship.…”

Herbivore teeth predict climatic limits in Kenyan ecosystems

“…In the terrestrial fossil record, functional relationships between traits of organisms and their environments may be examined through analysis of depositional environments (1), the sediment stable isotope record (2) the fossils themselves (3), or the changing structure of the fossil communities. Several approaches are available for the latter, including taxic methods based on the characteristics of the nearest living relatives (4) and methods based directly on functional properties of the fossils themselves (5). All of these approaches have their limitations and advantages, ranging from high cost and limited availability of data to poor resolution and the risk of circular reasoning.…”