The Sumatran rhino is currently one of the most endangered animals on Earth, status that hasn’t changed much the past million of years. This was revealed by a new study, developed by scientists from Marshall University of West Virginia. They wanted to see how the species evolved over time, and discovered that it had suffered extinction threads for a huge period of time.
For this complex study, researchers performed the first mapping of the Sumatran rhino genome. This way, they could look at the evolutionary path of the species, and the factors which influenced it over time. This way, they could identify when its long-lasting trouble started.
Everything took place during the last Ice Age. During that time, the first humans were moving from Africa to Asia and Europe, and the land was populated by the now-extinct mammoths or sabretooth mammals. The decline of the Sumatran rhino got more severe over millions of years, until only 200 specimens were left alive in the wilderness in 2011.
Constant habitat loss drove the Sumatran rhino closer to extinction
For the genome sequencing process, researchers collected DNA from one single male specimen, currently living at the Cincinnati Zoo. Herman Mays, one of the researchers, explained how the animal’s journey went.
“Our genome sequence data revealed the Pleistocene was a roller coaster ride for Sumatran rhinoceros populations.”
About 900,000 years ago, there came a moment for the Sumatran rhino when its populations reached a peak. This was the moment when they invaded Southeast Asia. Then, 12,000 years ago, many animals suffered a decline. Back then, sea level increased, and big pieces of land were lost underwater. This was a huge blow to the Sumatran rhino populations, as suitable land became less accessible. As habitat loss became more severe, their numbers kept decreasing.
The genetic sequence revealed that, 950,000 years ago, the Sumatran rhino population had reached 57,800 individuals. About 9,000 years ago, this population had decreased to only 700 individuals, showing how harsh a path this species had to undertake.