Phylogeography Of The Least Horseshoe Bat (Rhinolophus Pusillus)

Phylogeographic structure,genetic diversity pattern,and population history are based on both sufficient sampling,and the mutual verification and complementation between genetic markers and phenotypic variables.Studies on phylogeography mostly relied on paternal or maternal genetic markers(e.g.mitochondrial DNA,mtDNA),and occasionally on nuclear genetic markers.Previous studies on Rhinolophus pusillus were mostly based on Cytb or phenotypic variables,suggesting weak phylogeographic structure and narrow intraspecific phenotypic variation.We should treat these results cautiously because of lacking support from ncDNA and insufficient sampling.R.pusillus and R.monoceros have long been considered to be historically related to each other,although the detailed correlation is not clear and the mutual evolutionary relationship is also controversial.To elucidate the intraspecific and interspecific issues on R.pusillus,we performed range-wide phylogeography studies of R.pusillus and incidence analysis of population history between R.pusillus and R.monoceros.Based on two types of genetic marker: mitochondrial DNA(mt DNA)and nuclear gene fragment(ncDNA),we reconstructed the phylogeography structure,genetic diversity pattern and population history of R.pusillus,and also the evolutionary relationship between the R.pusillus and R.monoceros.Then,we explored the influence of paleoclimatic and paleogeological changes on the population history,and the association of population history between R.pusillus and R.monoceros.By using ecological niche model(ENM),we derived the current distribution and historical distribution pattern of R.pusillus.The results were then used to elucidate the influence of habitat suitability changes on the population history.Besides,with the aim of exploring pattern of genealogical geography in East Asia,we further explored the association among genealogy origin,history of expansion,refuge in glacier period,and the migration route.Lastly,based on the climatic model of global warming,we reconstructed the distribution pattern of R.pusillus during 2080 – 2099.Finally,the following conclusions were got:1)R.monoceros and R.pusillus were mtDNA monophyletic groups with incomplete lineage sorting(ILS)of the ncDNA.The most recent common ancestor(TMRCA)analysis and reconstruction of ancestral distributions(RASP)indicated that R.pusillus colonized to the central part of Taiwan island through the land bridge during glacier period and formed R.monoceros.Because of the short divergence time,ILS did happen.There was a significant difference between R.pusillus and R.monoceros in the call frequency,but the difference between R.pusillus and the ancestral population of R.monoceros was not significant.Further analysis concluded that the difference of call frequency between R.monoceros and R.pusillus was mostly the results of intraspecific divergence of R.monoceros.2)According to phylogeography structure and genetic diversity pattern of mtDNA,R.pusillus was classified into six geographic groups.The southern population group is the ancestral populations and mainly distributed around the Nanling Mountains,exhibiting high genetic diversity and phenotypic diversity.Since the middle of the Pleistocene,the multidirectional expansion of southern population groups formed four geographical groups surrounding the Nanling areas: East China,Central China,Hainan,and Yunnan population groups.The paleoclimatic fluctuation,paleogeological changes,also refuge segregation formed a star-like lineage distribution pattern of R.pusillus centered on the southern population group.The niche model indicated two refuges in Nanling and Wuyishan areas respectively.The two refuges were likely to be connected from each other during the glacier periods,or the isolation was weak.Specially,the recent expansion of the Eastern,Central,and Southern population groups has formed a mixed group of different lineages in the Shandong region.The founder effect and intraspecific competition contributed to a decrease of the genetic diversity.3)Notably,the niche model during 2080 – 2099 reminded us that the suitability of Nanling and Wuyishan areas would be significantly reduced under the backdrop of global warming,and islands(such as Hainan Island and Taiwan Island)would be in the same situation.Above results could be important reference for the habitat protection of R.pusillus in the future.