Whole genome and haplotype analyses indicate the Chinese red panda and Himalayan red panda are two distinct species with differing evolutionary histories.
The red panda (Ailurus fulgens) is an endangered mammal native to the Himalayan Mountains. It was once ubiquitous across Eurasia but is now found only at the south-eastern and southern edges of the Qinghai-Tibetan Plateau.
Latest research by Professor Wei Fuwen from the Institute of Zoology, Chinese Academy of Sciences, suggests that there are actually two distinct species of red panda: the Chinese red panda (Ailurus styani) and the Himalayan red panda (Ailurus fulgens).
Professor Wei’s team performed whole genome resequencing on 65 wild red pandas from seven geographical populations. Data from 49 of them were used to compare their haplotypes (variations in DNA inherited from a single parent) i.e. mitochondrial DNA, which is inherited from the mother, and Y chromosomes, which are inherited from the father.
Results from all three markers found substantial genetic divergence between the two species. Compared with Chinese red pandas, the Himalayan red pandas had 50 percent fewer DNA mutations. The haplotypes also clustered together in different regions of the genomes, and there were no shared Y chromosome variants between the two. The team says these differences are reflected in their appearances, with Chinese red pandas having redder faces and more prominent tail rings.
Further analysis also found that the Yalu Zangbu River, rather than the Nujiang River as previously believed, is most likely the geographical boundary between the two species. This satisfies decades-old criticisms regarding morphological similarity of red pandas on both sides of the Nujiang River.
Lastly, the genome resequencing data revealed clearly different evolutionary histories for the two species. Himalayan red pandas experienced three population bottlenecks – with the most recent decline taking place only 90,000 years ago – and one very small expansion. This has resulted in low genetic diversity and small population size today. In contrast, Chinese red pandas experienced two population bottlenecks – most likely due to glacial periods, but they managed to recover after each event – and one large expansion.
Hu Yibo, first author of the study published in Science Advances, hopes the knowledge will boost conservation efforts by enabling people working in the field to tailor their methods according to the species and avoid any missteps. For example, knowing that there are two species could prevent interbreeding in captivity. “Interbreeding between species may harm the genetic adaptations already established for their local habitat environment,” said Hu. “This finding will help construct clear red panda pedigree in captivity. [APBN]