A family tree of all rhinos

The genomic status and relationships among rhinoceros species were recently presented in a new study, involving several researchers at CPG. Apart from newly sequenced DNA and previously published data from now living species, DNA was also sequenced from three extinct species; the woolly rhino, Merck ́s rhino and the so-called Siberian unicorn (Elasmotherium sibiricum). After comparing all genomes, a deep split was revealed between the African and Eurasian rhinos, going roughly 16 million years back in time. Another significant discovery was the relatively low levels of genetic diversity detected in all species throughout time. Seemingly, rhinos have adapted to small population sizes, and the low genetic diversity has not led to inbreeding problems or affected their health. However, when comparing modern rhinos with samples from historical and ancient individuals, there is a decreasing diversity seen, which ultimately could contribute to their extinction. The study is published in Open Access in the journal Cell: “Ancient and modern genomes unravel the evolutionary history of the rhinoceros family”. A good popular summary is available in Gizmodo.