Asian elephant (Elephas maximus). Photo Jester & Wylde Genome data has confirmed for the first time that the Asian elephant has four distinct subspecies. That is important information for protecting this endangered animal species.
For his PhD research, Jeroen Kappelhof (Animal Breeding and Genomics) analysed the DNA of 27 Asian elephants covering almost the entire area in which the species is found. The analysis shows there are four genetic clusters: Borneo, Sumatra, Sri Lanka and the Asian continent. This is the first time anywhere in the world that the Asian elephant genome has been analysed on this scale. It is also the first confirmation using genome data that the Sumatran elephant is a separate subspecies.
His analyses of the genetic material let him reconstruct the family tree of the Asian elephant, explains Kappelhof. ‘We see that their common ancestor split into two branches about 170,000 years ago, one on Borneo and Sumatra and one on Sri Lanka and the Asian continent. Shortly after that, Borneo and Sumatra split. It was only much later, about 48,000 years ago, that Sri Lanka and the continental mainland split.’
Kappelhof’s findings were published recently in Ecology and Evolution. They will help nature conservationists and zoos to make better choices for the conservation of the species, for example by restricting inbreeding or managing distinct populations separately. The Asian elephant is on the IUCN Red List as an endangered species; the Sumatran subspecies is even critically endangered.
DNA from zoos
Many of the DNA samples came from elephants kept in European zoos. Kappelhof started collecting the samples in 2022. ‘Between 35,000 and 50,000 Asian elephants are estimated to live in the wild. There are another 15,000 elephants in zoos around the world and in refuges in Asia. But complete genetic profiles had only been made and published for nine of those elephants,’ he said in a previous in-depth article on the topic in Resource.
Kappelhof’s analyses showed that the population of Asian elephants in European zoos is genetically highly diverse. ‘That offers opportunities for maintaining the diversity, as long as breeding is done carefully within each genetic cluster.’
