Negative global-scale association between genetic diversity and speciation rates in mammals
Ana C Afonso Silva, Odile Maliet, Leandro Aristide, David Nogués-Bravo, Nathan Upham, Walter Jetz , Hélène Morlon
Abstract
Genetic diversity is critical for species evolution and their adaptability to global changes, while speciation rate is critical for explaining large-scale patterns of species richness. Exploring correlates of variation in genetic diversity and speciation rates across species is a major interest of evolutionary biologists, but these two questions have mostly been investigated independently. Here, we assess the relationship between intra-specific genetic diversity and speciation rate for 1897 mammal species ( one third of the total diversity) covering all mammalian orders. We find a negative association between mitochondrial genetic diversity and speciation rate across mammalian clades globally. This association is not accounted for by differences in the ecological attributes of species. Our findings suggest a systematic link between micro- and macroevolutionary processes that need to be better understood and considered when investigating determinants of either genetic diversity or speciation rates.
Fig. 1 sub-title
Mammals species-level consensus phylogeny from Upham et al. (2019), with branches coloured with branch-specific speciation rates estimated with ClaDS2 (see color legend in the central inset).
Bars at tips reflect estimated within-species genetic diversity for those species with 5 or more cytochrome b sequences available : Tajima’s (inner circle, red color legend in the top right inset) and Watterson’s (outer circle, blue color legend). Central inset : distribution of tip speciation rates for all mammals (black line, shaded fill) and 14 clades with more than 20 species (coloured lines, no fill) ; Top-right inset : distribution of genetic diversity, log scaled following the same line colouration. Silhouette figures were contributed by various authors with a public domain license (public domain mark 1.0 ; CC0 1.0) from PhyloPic (http://phylopic.org). Source data are provided as a source data file.
Nat Commun. 2025 Feb 20 ;16(1):1796. doi : 10.1038/s41467-025-56820-y.
