Phylogenetic diversity as a window into the evolutionary and biogeographic histories of present-day richness gradients for mammals

Abstract

Phylogenetic diversity (PD) captures the shared ancestry of species, and is increasingly being recognized as a valuable conservation currency. Regionally, PD frequently covaries closely with species richness; however, variation in speciation and extinction rates and/or the biogeographic history of lineages can result in significant deviation. Locally, these differences may be pronounced. Rapid recent speciation or high temporal turnover of lineages can result in low PD but high richness. In contrast, rare dispersal events, for example, between biomes, can elevate PD but have only small impact on richness. To date, environmental predictors of species richness have been well studied but global models explaining variation in PD are lacking. Here, we contrast the global distribution of PD versus species richness for terrestrial mammals. We show that an environmental model of lineage diversification can predict well the discrepancy in the distribution of these two variables in some places, for example, South America and Africa but not others, such as Southeast Asia. When we have information on multiple diversity indices, conservation efforts directed towards maximizing one currency or another (e.g. species richness versus PD) should also consider the underlying processes that have shaped their distributions.

Spatial variation of mammal richness, functional and phylogenetic diversity in the Mexican transition zone

“…Thus, different historical, envi- ronmental and ecological processes may be structuring the mammal assemblages in the Mexican Transitional Zone, as has been reported in other regions (Davies and Buckley 2011, Cisneros et al 2014, González-Maya et al 2016a). …”

“…High phylogenetic diversity has been associated with the hypothesis of niche evolution as driver in the assemblages (Safi et al 2011, Cisneros et al 2014, thus indicating that historical factors, such as dispersal events, speciation and extinction may have shaped the phylogenetic relationships among extant species (Davies and Buckley 2011); nonetheless we must be cautious when the phylogenetic signal is not explicitly evaluated (Losos 2008). In contrast, other environmental processes (e.g., low trait evolution, relaxed competition) may be driving the biodiversity dimensions in the Nearctic and the Neotropical regions.…”

“…The main drawback of this approach is that species richness considers all species to be equally distinct. However in recent decades new approaches have emerged, incorporating other biodiversity dimensions to account for the ecological and evolutionary identity of species (Petchey et al 2004, Davies and Buckley 2011, Stevens and Gavilanez 2015. On one hand, functional diversity incorporates the ecological identity of species to assess the variation of functional traits that influence species fitness and ecological processes Gaston 2002, Mlambo 2014).…”

The PD Phylogenetic Diversity Framework: Linking Evolutionary History to Feature Diversity for Biodiversity Conservation

“…PD now is regarded as "a leading measure in quantifying the biodiversity of a collection of species" (Bordewich and Semple 2012 ) and as "a resonant symbol of the current biodiversity crisis" (Davies and Buckley 2011 ), with important applications at both regional /global (e.g. Forest et al 2007 ) and within-ecosystem scales (e.g.…”

Representing Hotspots of Evolutionary History in Systematic Conservation Planning for European Mammals

“…Evolutionary history is often quantified in community ecology for the purpose of understanding the diversity of current species distributions (Davies and Buckley 2011;Fritz and Rahbek 2012) or the potential functioning of ecosystems (Cadotte et al 2012), whereas applications to conservation have remained limited.…”