Evolutionarily distinct species are threatened by international trade

Abstract

Global wildlife trade involves thousands of species spanning the tree of life. Targeted exploitation of species risks eroding the accumulated evolutionary history of ecosystems, threatening species interactions and ecosystem resilience. A key issue is understanding how phylogenetic diversity and evolutionary distinctiveness of terrestrial vertebrates (birds, mammals, squamates, and amphibians) is utilized and protected in international trade under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Wild-sourced hotspots of exported phylogenetic diversity are found across Southern Africa and captive-breeding hotspots are in Europe and North America, whereas hotspots of imported phylogenetic diversity are shared across Asia, Europe, and North America. We find that for wild-sourced mammals, more evolutionarily distinct species are more likely to traded, but for the majority of taxa, from both wild and captive sources, there is no significant relationship between evolutionary distinctiveness and probability or volume of trade. Additionally, listed species are not more likely to be more evolutionarily distinct than those not listed. We identify 13 species without any CITES listing in the 10% of species with the greatest evolutionary distinctiveness values for their respective taxonomic group that are likely threatened by international trade. Acknowledging the heightened value and vulnerability of evolutionarily distinct, trade-threatened species necessitates the rapid development of context-specific trade management strategies to ensure that unsustainable trade, at all scales, does not drive extinctions among species that constitute disproportionate amounts of evolutionary history.

Keywords: CITES; evolutionary distinctiveness; phylogenetic diversity; sustainable trade; wildlife trade.