Regions defined by Holt et al.11. a, Biogeographical regions for vertebrates and their associated boundaries used in this study, as defined on the basis of phylogenetic faunistic turnover (ref. 11). b, Phylogenetic turnover (p-βsim; ref. 11) among bioregions. Regions may be clustered at different turnover thresholds. Clustering them at p-βsim = 0.33 results in bioregions corresponding to Holt et al.’s realms11, while clustering them at deeper p-βsim values results in bioregions very similar to the traditional biogeographical realms6,19. Biogeographical regions are: Af, African; Am, Amazonian; AS, Arctico–Siberian; Au, Australian; Ch, Chinese; Eu, Eurasian; GC, Guineo–Congolian; IM, Indo–Malayan; Ja, Japanese; Ma, Madagascan; Me, Mexican; NA, North American (= Nearctic); No, Novozelandic; Or, Oriental; Pa, Panamanian; PM, Papua-Melanesian; SA, South American; Sa, Saharo–Arabian; Ti, Tibetan. The Polynesian region is not shown. Figure adapted from ref. 11, AAAS.