Tracking Species in Space and Time: Assessing the Relationships Between Paleobiogeography, Paleoecology, and Macroevolution

Abstract

In all species, geographic range is constrained by a combination of ecological and historical factors. Ecological factors relate to the species' niche, its environmental or biotic limits in multidimensional space, while historical factors pertain to a species' ancestry, specifically the location at which a species evolved. Historical limitations are primary during speciation, while ecological factors control the subsequent expansion and contraction of species range. By assessing biogeographic changes during the lifespan of individual species, we can assess the relationship between paleobiogeography, paleoecology, and macroevolution. Quantitative paleobiogeographic analyses, especially those using GIS-based and phylogenetic methods, provide a framework to rigorously test hypotheses about the relationship between species ranges, biotic turnover, and paleoecology. These new tools provide a way to assess key questions about the co-evolution of life and earth. Changes in biogeographic patterns, reconstructed at the species level, can provide key information for interpreting macroevolutionary dynamics–particularly speciation mode (vicariance vs. dispersal) and speciation rate during key intervals of macroevolutionary change (biodiversity crises, widespread invasion events, and adaptive radiations). Furthermore, species ranges can be reconstructed using ecological niche modeling methods to examine the effects of environmental controls on geographic range shifts. Particularly fruitful areas of investigation in future paleobiogeographic analysis include (1) the relationship between species ranges and speciation events/mode, (2) relationship between shifting ecological regimes and range expansion and contraction, (3) the impact of interbasinal species invasions on both community structure and macroevolutionary dynamics, (4) the mechanics of transitions between endemic to cosmopolitan faunas at local, regional, and global scales, (5) how ecology and geographic range impacts species extinction during both background and crisis intervals.Three case studies are presented to illustrate both the methods and utility of this theoretical approach of using paleobiogeographic patterns to assess macroevolutionary dynamics. The first case study examines paleobiogeographic patterns in shallow marine invertebrates during the Late Devonian Biodiversity Crisis. During this interval, speciation by vicariance declined precipitously and only species exhibiting expanding geographic ranges survived the crisis interval. Patterns of biogeographic change during the Late Ordovician Richmondian invasion (Cincinnati Arch region) reveal similar patterns; speciation rate declines during invasion intervals and widely distributed endemic species are best able to survive in the new invasive regime. Phylogenetic biogeographic patterns during the Miocene radiation of North American horses suggest climatic parameters were important determinants of speciation and dispersal patterns.