Multilocus phylogeography and ecological niche modeling suggest speciation with gene flow between the two Bamboo Partridges

Background:Understanding how species diversify is a long-standing question in biology.The allopatric speciation model is a classic hypothesis to explain the speciation process.This model supposes that there is no gene flow during the divergence process of geographically isolated populations.On the contrary,the speciation with gene flow model supposes that gene flow does occur during the speciation process.Whether allopatric species have gene flow during the speciation process is still an open question.Methods:We used the genetic information from 31 loci of 24 Chinese Bamboo Partridges(Bambusicola thoracicus)and 23 Taiwan Bamboo Partridges(B.sonorivox)to infer the gene flow model of the two species,using the approxi-mate Bayesian computation(ABC)model.The ecological niche model was used to infer the paleo-distribution during the glacial period.We also tested whether the two species had a conserved ecological niche by means of a back-ground similarity test.Results:The genetic data suggested that the post-divergence gene flow between the two species was terminated before the mid-Pleistocene.Furthermore,our ecological niche modeling suggested that their ecological niches were highly conserved,and that they shared an overlapping potential distribution range in the last glacial maximum.Conclusions:The allopatric speciation model cannot explain the speciation process of the two Bamboo Partridges.The results of this study supported a scenario in which speciation with gene flow occurring between the allopatric species and have contributed to our understanding of the speciation process.

Southeast Asian primate communities:the effects of ecology and Pleistocene refuges on species richness

We examined historical and ecological factors affecting current primate biodiversity in Southeast Asia.In Africa,Madagascar and South America,but not Southeast Asia,primate species richness is positively associated with average rainfall and distance from the equator(latitude).We predicted that Southeast Asia’s non-conformance may be due to the effect of dispersed Pleistocene refuges(locations of constricted tropical forests during glacial maxima which today are at least 305 m in altitude).Based on 45 forested sites(13 on large islands;32 on the mainland)of at least 100 km^(2) to minimize recent human impact,we determined correlations between extant primate species richness and rainfall,latitude and supplementary ecological variables,while controlling for refuges and islands.We found that refuge sites had significantly higher primate species richness than non-refuges(t=-2.76,P<0.05),and distance from the nearest Pleistocene refuge was negatively correlated with species richness for non-refuge sites(r=-0.51,P<0.05).There was no difference in species richness between sites on large islands and the mainland(t=-1.4,P=0.16).The expected positive relationship between rainfall and species richness was not found(r=0.17,P=0.28).As predicted,primate species richness was negatively correlated with latitude(r=-0.39,P<0.05)and positively correlated with mean temperature(r=0.45,P<0.05).General linear models indicated that a site’s latitude(F_(1,38)=6.18,P<0.05)and Pleistocene refuge classification(F_(1,42)=5.96,P<0.05)were the best predictors of species richness.Both ecological and historical factors contribute to present day primate species richness in Southeast Asia,making its biodiversity less of an outlier than previously believed.