A global analysis of ecological and evolutionary drivers of the use of wild mammals in traditional medicine

Ingredients derived from wild mammals are widely used in traditional remedies. Large datasets of traits, geographic ranges, and phylogeny are also available for mammals. Therefore, mammals are an ideal group in which to explore the ecological (e.g. range size, body mass) and evolutionary (i.e. shared ancestry) correlates of the use of animal-derived products in traditional medicine. In a global analysis of correlates of the use of wild mammals in traditional medicine, we tested how life-history traits relate to the use of mammal products to treat disease. We compiled data from the primary literature about folk remedies based on mammals via a literature search using ISI Web of Knowledge, Scopus, and Google Scholar. Then, we used modern phylogenetic comparative methods to estimate phylogenetic signals in the diseases that mammal body parts are used to treat and to test whether geographic range size and body mass are related to medicinal use. We tested whether mammalian species that are used more in medicine are also those that are more threatened by extinction. Our results show that 521 mammalian species are used to source products to treat 371 ailments. We found support for the hypothesis that phylogenetic relatedness correlates with the use of mammal-derived remedies in traditional medicines. Specifically, we confirm our hypotheses that closely related species are more similar in terms of their perceived medical versatility than distantly related species and are used to treat similar diseases. Furthermore, we demonstrated that large marsupials are more versatile and are used to treat more diseases than smaller marsupials. In our database, 155 mammalian species are considered threatened (Vulnerable, Endangered, or Critically Endangered), and a further 46 are Near Threatened, suggesting that overexploitation for medicinal use could be an overlooked source of threat that should be considered in mammal species conservation assessments. We demonstrate that phylogenetic relatedness correlates with the use of mammalian species as remedies in traditional medicine, and urge future researchers to evaluate the negative effects of overexploitation of mammals for medical purposes. Such overexploitation could cause non-random extinction patterns in the mammalian tree of life.