Testing the phylogenetic gambit: how much functional diversity can we reliably conserve if we prioritize phylogenetic diversity?

Abstract

In the face of the biodiversity crisis, it is argued that we should prioritize species in order to capture high functional diversity (FD). Because species traits often reflect shared evolutionary history, many researchers have advocated for a \"phylogenetic gambit\": maximizing phylogenetic diversity (PD) should indirectly capture FD. For the first time, we empirically test this gambit using data from >15,000 vertebrate species and ecologically-relevant traits. Maximizing PD results in an average gain of 18% of FD relative to random choice. However, this average gain hides the fact that in over 1/3 of the comparisons, maximum PD sets contain less FD than randomly chosen sets of species. These results suggest that, while maximizing PD protection can help to protect FD, it represents a risky strategy.\n\nStatement of authorshipFM, MP, MC, SD, GVDR, RG, AOM, CT and WP conceived the design of the study. FM and GVDR conducted the analysis. FM, RG, MP and WP interpreted the results and wrote the first draft of the manuscript. All authors edited the final version.\n\nData accessibility statementMost of the data is publicly available (see methods). The Fish data is available upon request.\n\nCode accessibility statementR functions developed in this paper are available at https://github.com/FloMazel/FD_PD_Max