This is a photo by the researchers of the old panda fossil. Credit: Yingqi Zhang Xu Yong
Scientists in China found the fossil of a giant panda who lived 22,000 years ago. Until they dug up a fossil, put together again and analyzed his mitochondrial DNA, biologists had no idea that this panda origin still existed.
It is now regarded as the oldest DNA of the giant pandas to date, one of the researchers said.
The panda fossil turned up in Cizhutuo Cave in the Guangxi region in China. No pandas live there today, the researchers of the Chinese Academy of Sciences wrote in an article today (June 18) in the journal Current Biology. An unexpected giant panda fossil found was exciting, she wrote, because researchers do not have a good sense of the history of the 2,500 giant pandas living in the world today. Researchers know that 20 million years ago, the current batch of live giant pandas is separated from all other bears. They do not know much about their origin as.
This fossil, the researchers showed, was from a being that is separated from the living giant pandas much more recently: about 183,000 years ago. [Photos: The Life of a Giant Panda]
Before the researchers were able to determine that the timeline, but (and, in fact, before they were certain that the fossil came from a separate species), the researchers had to re-construct the small fragments of the DNA in the mitochondria that remained after millenia in a tropical cave. (Mitochondrial DNA is distinct from the DNA found in the nucleus of a cell, but provides similar information about a creature’s origin.)
Pull that off, researchers fit 148,329 DNA fragments together like a puzzle, with the help of a living giant pandas mitochondrial DNA as a guide. All of the fragments come from one individual, and all together, the researchers were able to use them for the parse of the animal origin.
The DNA also had dozens of mutations that would have changed how the animal is developed, the researchers said. She suggested that changes are adaptations to survive in the cooler climate of the subtropics during the ice age 22,000 years ago.
Originally published on Live Science.