Dispersal and niche evolution jointly shape the geographic turnover of phylogenetic clades across continents

Abstract

The turnover of phylogenetic clades across space is a fundamental biodiversity pattern that may depend on long-term evolutionary processes, and that has downstream effects on other aspects of diversity including species richness and community structure. Limited niche evolution and limited dispersal are two major processes causing spatial restriction, and thus turnover, of clades. We studied the determinants of clade turnover within the World's richest floristic kingdom, the Neotropics, using the palm family (Arecaceae) as a model. We show that continental-scale clade turnover is driven by a combination of limited niche evolution — with respect to temperature and soil tolerances — and limited dispersal. These findings are consistent with strong dispersal barriers within the Neotropics, and the observation that some palm lineages are most diverse in certain biomes or climates. The importance of such deep-time effects suggest that palms might be slow to adapt or disperse in response to anthropogenic climate change.

Tropical rain forest evolution: palms as a model group

“…Using macroecological methods [5], palm species richness has been shown to be strongly determined by contemporary climatic variables, but the influence of Quaternary climate as well as deeper time biogeographic processes has also been highlighted. By combining distribution data with information from the dated phylogeny [4], a strong imprint on phylogenetic relatedness of geographic isolation and in situ diversification has been found, especially in South America and palm-rich islands such as Madagascar, which is indicative of strong dispersal limitation, a pattern also recovered in a further study focused on the Neotropical palms [9]. …”

“…In particular, dated phylogenies of tropical rain forest lineages can be used to unravel the evolutionary origins, timescales and processes of this biome as a whole. In this comment, we describe how one such tropical rain forest-restricted lineage, the palm family, has provided evidence of global rain forest history in a succession of recent studies integrating a range of basic biodiversity datasets [3-9], the first of which was published in BMC Biology [3], and now represents a model for the study of the tropical rain forest biome that may, potentially, be applied to other lineages of organisms.…”

Single nucleotide polymorphism‐based dispersal estimates using noninvasive sampling

“…Very short-distance dispersers can have a considerable effect on conservation issues such as inbreeding and population genetic structure (Greenwood 1980; Eiserhardt et al. 2013). We therefore opted to include all natal dispersal distances to appropriately describe dispersal patterns.…”

Neutral Theory Overestimates Extinction Times in Nonhuman Primates

“…Specific explanations for nonlinear or neutral diversification patterns will require further work to investigate the tempo of diversification in relation to historical characteristics and the ecological features of each taxon (Baker et al 2014;Eiserhardt et al 2013;FitzJohn 2012;Magnuson-Ford and Otto 2012;Maia et al 2013). An evaluation of interactions between primates and plants found that diversification rates of mutualistic species are higher than those of antagonistic species (Gómez and Verdú 2012).…”