Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We ex...Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We examined SD and GV patterns for this species by using multivariate statistical analyses of external morphological characters scored from specimens from the China's Mainland. The result displayed that SD was significant in several external characters in P. mucrosquamatus, and the male P. mucrosquamatus formed two distinct clusters（Hainan Island and China's Mainland）, but the females did not. Based on our present work and the other data, we concluded that no significantly intraspecific differentiation is present within this species.展开更多
Most plants can reproduce both sexually and asexually(or vegetatively),and the balance between the two reproductive modes may vary widely between and within species.Extensive clonal growth may affect the evolution of ...Most plants can reproduce both sexually and asexually(or vegetatively),and the balance between the two reproductive modes may vary widely between and within species.Extensive clonal growth may affect the evolution of life history traits in many ways.First,in some clonal species,sexual reproduction and sex ratio vary largely among popula-tions.Variation in sexual reproduction may strongly affect plant’s adaptation to local environments and the evolution of the geographic range.Second,clonal growth can increase floral display,and thus pollinator attraction,while it may impose serious constraints and evolutionary challenges on plants through geitonogamy that may strongly influence pollen dispersal.Geitonogamous pollination can bring a cost to plant fitness through both female and male functions.Some co-evolutionary interactions,therefore,may exist between the spatial structure and the mating behavior of clonal plants.Finally,a trade-off may exist between sexual reproduction and clonal growth.Resource allocation to the two reproduc-tive modes may depend on environmental conditions,com-petitive dominance,life span,and genetic factors.If different reproductive modes represent adaptive strategies for plants in different environments,we expect that most of the resources should be allocated to sexual reproduction in habitats with fluctuating environmental conditions and strong competition,while clonal growth should be dominant in stable habitats.Yet we know little about the consequence of natural selection on the two reproductive modes and factors which control the balance of the two reproductive modes.Future studies should investigate the reproductive strategies of clonal plants simultaneously from both sexual and asexual perspectives.展开更多
基金funded by the National Natural Science Foundation of China (NSFC31372152)the Scientific Research Fund of Sichuan Provincial Education Department (13TD0027) to Peng Guo
文摘Sexual dimorphism（SD） and geographic variation（GV） are widespread in snakes. Protobothrops mucrosquamatus（Cantor 1839） is one of the most common Asian venomous snakes with a wide geographical distribution. We examined SD and GV patterns for this species by using multivariate statistical analyses of external morphological characters scored from specimens from the China's Mainland. The result displayed that SD was significant in several external characters in P. mucrosquamatus, and the male P. mucrosquamatus formed two distinct clusters（Hainan Island and China's Mainland）, but the females did not. Based on our present work and the other data, we concluded that no significantly intraspecific differentiation is present within this species.
基金This work was financially supported by the National Natural Science Foundation of China(No.30430160)the Doctoral Program for Higher Education(No.20030027021).
文摘Most plants can reproduce both sexually and asexually(or vegetatively),and the balance between the two reproductive modes may vary widely between and within species.Extensive clonal growth may affect the evolution of life history traits in many ways.First,in some clonal species,sexual reproduction and sex ratio vary largely among popula-tions.Variation in sexual reproduction may strongly affect plant’s adaptation to local environments and the evolution of the geographic range.Second,clonal growth can increase floral display,and thus pollinator attraction,while it may impose serious constraints and evolutionary challenges on plants through geitonogamy that may strongly influence pollen dispersal.Geitonogamous pollination can bring a cost to plant fitness through both female and male functions.Some co-evolutionary interactions,therefore,may exist between the spatial structure and the mating behavior of clonal plants.Finally,a trade-off may exist between sexual reproduction and clonal growth.Resource allocation to the two reproduc-tive modes may depend on environmental conditions,com-petitive dominance,life span,and genetic factors.If different reproductive modes represent adaptive strategies for plants in different environments,we expect that most of the resources should be allocated to sexual reproduction in habitats with fluctuating environmental conditions and strong competition,while clonal growth should be dominant in stable habitats.Yet we know little about the consequence of natural selection on the two reproductive modes and factors which control the balance of the two reproductive modes.Future studies should investigate the reproductive strategies of clonal plants simultaneously from both sexual and asexual perspectives.
