Mitochondrial phylogeography and subspecific variation in the red panda (Ailurus fulgens): implications for...

The red panda (Ailurus fulgens) is an endangered species and its present distribution is restricted to isolated mountain ranges in western China (Sichuan, Yunnan, and Tibet provinces) and the Himalayan Mountains chain of Nepal, India, Bhutan, and Burma. To examine the evolutionary history across its current range, and to assess the genetic divergence among current subspecies and population structure among different geographic locations, we sequenced mitochondrial DNA from the control region (CR) and cytochrome (cyt) b gene for 41 individuals in Sichuan, Yunnan, Tibet of China, and Burma. 25 CR haplotypes (10 for cyt b) were identified from 11 geographic locations. Only three haplotypes were shared among sample localities, including one among current subspecies. Nine haplotypes were shared with the study of Su et al. [Mol. Biol. Evol. 18 (2001) 1070]. CR haplotype diversity was high (0.95+/-0.02) and nucleotide diversity among all haplotypes was relatively low (0.018+/-0.009). Phylogenetic confirmed trees show a shallow pattern with very little structure or statistical robustness. The application of two coalescent-based tests for population growth allowed us to interpret this phylogeny as the result of a recent population expansion. Analysis of molecular variance and nested clade analysis failed to detect significant geographic structure in both data sets. The lack of significant differentiation between subspecies does not indicate the presence of evolutionary significant units. We suggest that the present population structure has resulted from habitat fragmentation and expansion from glacial refugia. Due to its habitat requirements it is likely that the red panda has undergone bottlenecks and population expansions several times in the recent past. The present population may exhibit a pattern reminiscent of a relatively recent population expansion.