When our ancestors wandered across Asia some 80,000 years ago, they would have come face to face with a whole menagerie of beasts no longer around today, from towering mammoths to the largest tortoises ever known.
But they would also have likely come across another creature now extinct: a completely distinct type of giant panda.
In the caves of Guangxi Province, China, researchers discovered the ancient remains of a giant panda dating to 22,000 years old. But there was a catch, as today there are no pandas living in this lush mountainous region that borders Vietnam to the south. With the paucity of ancient giant panda fossils – due in large part to the fact that they live in wet, humid environments – this find represents a rare opportunity to study the black-and-white creature’s past.
Publishing their results in the journal Current Biology, the team of researchers from the Chinese Academy of Sciences detailed how they were able to extract mitochondrial DNA (mtDNA) from the skull that had been found in the Cizhutuo cave. This gave the researchers a rare glimpse into the ancient matrilineal line of giant pandas.
By comparing what they could sequence with that of modern-day panda’s in addition to 32 other ancient bears, they could build up a more detail picture of the giant panda’s evolutionary history.
“Using a single complete mtDNA sequence, we find a distinct mitochondrial lineage, suggesting that the Cizhutuo panda, while genetically more closely related to present-day pandas than other bears, has a deep, separate history from the common ancestor of present-day pandas,” explains the Chinese Academy of Sciences’s Qiaomei Fu, in a statement.
The results found that the last common ancestor between the modern panda and the Cizhutuo panda was living between 144,000 and 227,000 years ago, but that this now extinct variety was living and evolving in parallel to the modern bear rather than representing the archaic type.
Today, the 2,500 surviving wild giant pandas are limited to a few mountain ranges in central China, but once were much more widespread. Comparing the genes between the modern panda and the now extinct one, they found a handful of mutations in the Cizhutuo panda that could represent local adaptations to the more southern habitat in which they once lived.
The team now want to try and extract the nuclear genome of the Cizhutuo panda and compare that with the modern variety, to see if that could help reveal any more secrets of the enigmatic bears' ancient past.