After the retreat of the Penultimate Glaciations, giant panda's second population expansion happened and it reached its population peak between 30~50 thousand years (kyr) ago. The warm weather in the Greatest Lake Period (30~40 kyr ago) and alpine conifer forest may play an important role in the flourishing of the panda population. However, during the period of last glacial maximum (LGM), the climate was cold, dry, and inhospitable with frequent storms and a dust-laden atmosphere. Under such harsh environment, extensive panda habitats were loss and its second population bottleneck occurred.
The more recent panda population history showed that the panda population separated into Qinling (QIN) and non-QIN populations at about 0.3Myr ago, and then the non-QIN cluster diverged into two populations, the Minshan (MIN) and Qionglai-Daxiangling-Xiaoxiangling-Liangshan (QXL) at about 2.8 KYA ago. Subsequently, the three populations were different in the ways of fluctuation. For example, there was a drastic decline in the QIN, a slight increase in the MIN and a more remarkable growth in the QXL populations.
Researchers identified the signals of panda's local adaptation. They found the largest group of selected genes in these populations was related to sensory system. However, the two genes, Tas2r49 and Tas2r3, were associated with bitter taste and were under directional selection between the QIN and non-QIN populations, showing no signal of directional selection between MIN and QXL populations.
As a form of olfactory communication, odor perception is crucial for reproduction and survival
|Contact: Jia Liu|