Liu S, Westbury MV, Dussex N, Mitchell KJ, Sinding MS, Heintzman PD, Duchêne DA, Kapp JD, von Seth J, Heiniger H, Sánchez-Barreiro F, Margaryan A, André-Olsen R, De Cahsan B, Meng G, Yang C, Chen L, van der Valk T, Moodley Y, Rookmaaker K, Bruford MW, Ryder O, Steiner C, Bruins-van Sonsbeek LGR, Vartanyan S, Guo C, Cooper A, Kosintsev P, Kirillova I, Lister AM, Marques-Bonet T, Gopalakrishnan S, Dunn RR, Lorenzen ED, Shapiro B, Zhang G, Antoine PO, Dalén L, Gilbert MTP
Cell 184 (19) 4874-4885.e16 [2021-09-16; online 2021-08-24]
Only five species of the once-diverse Rhinocerotidae remain, making the reconstruction of their evolutionary history a challenge to biologists since Darwin. We sequenced genomes from five rhinoceros species (three extinct and two living), which we compared to existing data from the remaining three living species and a range of outgroups. We identify an early divergence between extant African and Eurasian lineages, resolving a key debate regarding the phylogeny of extant rhinoceroses. This early Miocene (∼16 million years ago [mya]) split post-dates the land bridge formation between the Afro-Arabian and Eurasian landmasses. Our analyses also show that while rhinoceros genomes in general exhibit low levels of genome-wide diversity, heterozygosity is lowest and inbreeding is highest in the modern species. These results suggest that while low genetic diversity is a long-term feature of the family, it has been particularly exacerbated recently, likely reflecting recent anthropogenic-driven population declines.