Speciation has never been directly observed in nature because it is a lengthy phenomenon.Although rare,ring species are an optimal natural example of speciation and can be identified through the assessment of the geog...Speciation has never been directly observed in nature because it is a lengthy phenomenon.Although rare,ring species are an optimal natural example of speciation and can be identified through the assessment of the geographical conditions of their potential habitat.Phrynocephalus forsythii is endemic to the Tarim Basin,which compnses the Taklamakan Desert and surrounded by mountains on three sides.This study aimed to determine whether P.forsythii had a ring-species-like divergence pattern through the characterization of the genetic features of 17 populations covering the major distribution of this species.Species distribution modelling revealed that P.forsythii had a continuous circular distribution around the Tarim Basin.Gene flow was observed in most adjacent populations except for two terminal populations of the ring,which exhibit the highest differentiation.Genetic distance and geographic distance were significantly correlated,indicating that the observed differentiation resulted from genetic variation gradually accumulating during population dispersion.Although our results do not definitively indicate that P.forsythii is a ring species,our results indicate a ring-shaped diversification This phenomenon elucidates the potential mechanism underlying speciation in the presence of gene flow,providing insight into this evolutionary process.展开更多
The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or env...The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.展开更多
基金supported by the National Natural Science Foundation of China (No.31471988 and No.31200287)。
文摘Speciation has never been directly observed in nature because it is a lengthy phenomenon.Although rare,ring species are an optimal natural example of speciation and can be identified through the assessment of the geographical conditions of their potential habitat.Phrynocephalus forsythii is endemic to the Tarim Basin,which compnses the Taklamakan Desert and surrounded by mountains on three sides.This study aimed to determine whether P.forsythii had a ring-species-like divergence pattern through the characterization of the genetic features of 17 populations covering the major distribution of this species.Species distribution modelling revealed that P.forsythii had a continuous circular distribution around the Tarim Basin.Gene flow was observed in most adjacent populations except for two terminal populations of the ring,which exhibit the highest differentiation.Genetic distance and geographic distance were significantly correlated,indicating that the observed differentiation resulted from genetic variation gradually accumulating during population dispersion.Although our results do not definitively indicate that P.forsythii is a ring species,our results indicate a ring-shaped diversification This phenomenon elucidates the potential mechanism underlying speciation in the presence of gene flow,providing insight into this evolutionary process.
基金supported by the National Natural Science Foundation of China (No.31471988 and N0.31200287)。
文摘The gut microbiota has gained attention because of its importance in facilitating host survival and evolution.However,it is unclear whether gut microbial communities are determined by the host(heritable factor) or environment(environmental factor).In this study,we investigated the gut microbial communities and potential functional signatures of two sympatric species distributed along an elevation gradient,the toadheaded lizards Phrynocephalus axillaris and P.forsythii.Our results indicated that at high elevations,the gut microbial communities of P.axillaris and P.forsythii did not significantly differ,and the phylogenetic relationships of gut microbial communities contradicted their hosts.At low altitudes,the two lizards could be distinguished based on their significantly different gut microbial communities.Compared to low-altitude populations,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that at higher altitudes,energy metabolism,such as carbohydrate,lipid,and amino acids metabolism were higher in both lizards.While a larger number of pathogenic bacteria were found in the lowaltitude population of P.forsythii.This suggests that the convergence of gut microbiota of two lizards at highaltitude stem from environmental factors,as they were exposed to the same environmental stress,whereas the divergence at low-altitude stemmed from heritable factors,as they were exposed to different environmental stresses.These results provide a new perspective regarding whether heritable or environmental factors dominate the gut microbiota during exposure to environmental stress.
