Biome shifts and niche evolution in plants

Abstract

What factors influence whether a lineage can successfully transition into a new biome, and why have some biome shifts been more frequent than others? To orient this line of research we develop a conceptual framework in which the likelihood of a biome shift is a function of (a) exposure to contrasting environments over time, (b) the evolutionary accessibility of relevant adaptations, and (c) changing biotic interactions. We evaluate the literature on biome shifts in plants in relation to a set of hypotheses on the size, connectedness, and absolute age of biomes, as well as on the adaptability of particular lineages and ecological interactions over time. We also critique the phylogenetic inference of past biomes and a "global" model-based approach to biome evolution. More robust generalizations about biome shifts will require detailed studies of well-sampled and well-resolved clades, accounting for changes in the relevant abiotic and biotic factors through time.