Study On The Population Structure And Historical Dynamics Of Rhiniopithecus Roxellana In The Qinling Mountains And Bachelor Groups In Primate Multilevel Society Facilitate Gene Flow Across Fragmented Habitats

With the continuous growth of human population size and environmental changes,more and more animals would be extinct due to the influence of human activities.In addition,the function of the social organization on endangered species is also an important scientific problem to be solved urgently.Based on individual identification and genetics analysis,our study focused on a flagship species-Rhiniopithecus roxellana in the Qinling Mountains.On the one hand,we study the population structure and dynamic history of R.roxellana,on the other hand,according to its complex social structure,the multilevel society;we revealed the all-male band(AMB)could play an important role in resisting the negative effects of habitat fragmentation.Wiht the above two aspects of research,we get the following results.First of all,we depicted the genetic structure and evolutionary history via microsatellite markers and combination with the ecological niche models(ENMs)to elucidate the intraspecific divergent and the impacts of the population demography on our focal species.Our results revealed three distinct subpopulations of R.roxellana,three of them populations could be structured into one lineage,revealing they had the same genetic background.We also uncovered asymmetric historical and symmetric contemporary gene flow existed.Our evolutionary dynamics analyses based on DIYABC suggested that the intraspecific divergence accompanied with effective population sizes changes.The ENMs result implied that the distribution range of this species experienced expansion during the last glacial maximum(LGM).Our results highlighted that geological factors could contribute to the high genetic differentiation within the R.roxellana in the Qinling Mountains.Secondly,it is well known that habitat fragmentation could reduce gene flow among populations,which may lead to reduction of genetic diversity,bottleneck and inbreeding depression.These situations are commonly seen among endangered species,particularly,in nonhuman primates.Despite this,a few endangered primate species could avoid these deleterious effects.In this study of the golden snub-nosed monkeys with multilevel social society(MLS),we demonstrate that social organization can mitigate the negative effects of habitat fragmentation.Generally,samples were collected from four isolated breeding populations and one all-male population in the Mt Qinling,China.Following population genetic analyses with 13 microsatellite loci,our results provide the first evidence that social structure can lead to genetic exchanges among the groups.That is,the enlarged all-male population can redistribute genetic variation in the MLS,which may compensate for negative effects due to habitat fragmentation.This social mechanism seems to play an essential role in maintainingthe genetic diversity among isolated groups,and reducing the risk of inbreeding depression.As MLS structure always with the aggregation of social groups,thus,we predicted that this complex social system was beneficial for the adaptation to environmental mechanism.In a word,we studied the genetic structure and evolutionary history of R.roxellana in the Qinling Mountains,central China.Moreover,we found its special social structure may provide chances to deal with the fragmented habitat.This research also sheds light on the underlying evolutionary dynamics of other species with similar social complexities,including humans.