Mediated by pollenflow,natural hybridization is deemed a crucial factor that propels speciation infloral plants.Despite the fact that the diversity of Epimedium species is concentrated mainly in Southwestern China,the p...Mediated by pollenflow,natural hybridization is deemed a crucial factor that propels speciation infloral plants.Despite the fact that the diversity of Epimedium species is concentrated mainly in Southwestern China,the poten-tial impact of interspecific pollination on natural hybridization has yet to be empirically scrutinized.To explore this,we studied theflowering period and the visitors offlowers in three frequently overlapping Epimedium species at Jinchengshan National Forest Park,located in Nanchong,Sichuan Province.Additionally,we performed a ser-ies of pollination experiments to examine breeding systems and hybrid compatibility.Morphologically,Epime-dium pubescens and Epimedium wushanense are clearly distinct and easily recognizable byflower morphology,while the putative hybrid is morphologically intermediate between them.Our observation revealed that E.pub-escens and E.wushanense had 15 days of overlapping anthesis.Both species are self-incompatible and require pol-linator services for successful reproduction.Although their pollinators differ in quantity and species,Lasioglossum sp.(Hymenoptera:Halictidae)visited all three species.Artificial pollination revealed no breeding barriers among the three species,and the resulting hybrid seeds exhibited fertility.The overlapping time offlowering,commonfloral visitors,and compatibility of hybrids may be important factors contributing to successful interspecific pol-lination and speciation for natural hybrid species of E.pubescens and E.wushanense.Consequently,the role of potential interspecific pollination is crucial for hybrid speciation and the evolutionary dynamics of Epimedium species.展开更多
The Cambrian Explosion is one of the most significant events in the history of life;essentially all easily fossilizable animal body plans first evolved during this event. Although many theories have been proposed to e...The Cambrian Explosion is one of the most significant events in the history of life;essentially all easily fossilizable animal body plans first evolved during this event. Although many theories have been proposed to explain this event, its cause remains unresolved.Here, we propose that the elevated level of oxygen, in combination with the increased mobility and food intake of metazoans, led to increased cellular levels of reactive oxygen species（ROS）, which drove evolution by enhancing mutation rates and providing new regulatory mechanisms. Our hypothesis may provide a unified explanation for the Cambrian Explosion as it incorporates both environmental and developmental factors and is also consistent with ecological explanations for animal radiation. Future studies should focus on testing this hypothesis, and may lead to important insights into evolution.展开更多
基金This research was supported by the Natural Science Foundation of Sichuan Province(No.2023NSFSC1282)the National General Cultivation Project of China West Normal University(No.19B029)Youth Foundation Specialization of West China Normal University(No.22KB004).
文摘Mediated by pollenflow,natural hybridization is deemed a crucial factor that propels speciation infloral plants.Despite the fact that the diversity of Epimedium species is concentrated mainly in Southwestern China,the poten-tial impact of interspecific pollination on natural hybridization has yet to be empirically scrutinized.To explore this,we studied theflowering period and the visitors offlowers in three frequently overlapping Epimedium species at Jinchengshan National Forest Park,located in Nanchong,Sichuan Province.Additionally,we performed a ser-ies of pollination experiments to examine breeding systems and hybrid compatibility.Morphologically,Epime-dium pubescens and Epimedium wushanense are clearly distinct and easily recognizable byflower morphology,while the putative hybrid is morphologically intermediate between them.Our observation revealed that E.pub-escens and E.wushanense had 15 days of overlapping anthesis.Both species are self-incompatible and require pol-linator services for successful reproduction.Although their pollinators differ in quantity and species,Lasioglossum sp.(Hymenoptera:Halictidae)visited all three species.Artificial pollination revealed no breeding barriers among the three species,and the resulting hybrid seeds exhibited fertility.The overlapping time offlowering,commonfloral visitors,and compatibility of hybrids may be important factors contributing to successful interspecific pol-lination and speciation for natural hybrid species of E.pubescens and E.wushanense.Consequently,the role of potential interspecific pollination is crucial for hybrid speciation and the evolutionary dynamics of Epimedium species.
基金supported by the Program of Co-Construction with the Beijing Municipal Commission of Education of ChinaFundamental Research Funds for the Central Universities (No. 2015KJJCB19)
文摘The Cambrian Explosion is one of the most significant events in the history of life;essentially all easily fossilizable animal body plans first evolved during this event. Although many theories have been proposed to explain this event, its cause remains unresolved.Here, we propose that the elevated level of oxygen, in combination with the increased mobility and food intake of metazoans, led to increased cellular levels of reactive oxygen species（ROS）, which drove evolution by enhancing mutation rates and providing new regulatory mechanisms. Our hypothesis may provide a unified explanation for the Cambrian Explosion as it incorporates both environmental and developmental factors and is also consistent with ecological explanations for animal radiation. Future studies should focus on testing this hypothesis, and may lead to important insights into evolution.
