马萨诸塞大学阿默赫斯特分校(University of Massachusetts Amherst,以下简称Umass Amherst)1903年开始设立园林本科专业,其风景园林教育经历了百年的发展,形成了一套行之有效的专业教学体系,其核心思想是:重视基础训练,紧跟学科前沿,...马萨诸塞大学阿默赫斯特分校(University of Massachusetts Amherst,以下简称Umass Amherst)1903年开始设立园林本科专业,其风景园林教育经历了百年的发展,形成了一套行之有效的专业教学体系,其核心思想是:重视基础训练,紧跟学科前沿,坚持专业特色。Umass Amherst风景园林专业教育实践证明,这是学科教育健康可持续发展不可获缺的三驾马车。这对我国风景园林本科教育非常具有借鉴意义。展开更多
Understanding speciation has long been a fundamental goal of evolutionary biology.It is widely accepted that speciation requires an interruption of gene flow to generate strong reproductive isolation between species.T...Understanding speciation has long been a fundamental goal of evolutionary biology.It is widely accepted that speciation requires an interruption of gene flow to generate strong reproductive isolation between species.The mechanism of how speciation in sexually dichromatic species operates in the face of gene flow remains an open question.Two species in the genus Chrysolophus,the Golden Pheasant(C.pictus)and Lady Amherst’s Pheasant(C.amherstiae),both of which exhibit significant plumage dichromatism,are currently parapatric in southwestern China with several hybrid recordings in field.In this study,we estimated the pattern of gene flow during the speciation of the two pheasants using the Approximate Bayesian Computation(ABC)method based on data from multiple genes.Using a newly assembled de novo genome of Lady Amherst’s Pheasant and resequencing of widely distributed individuals,we reconstructed the demographic history of the two pheasants by the PSMC(pairwise sequentially Markovian coalescent)method.The results provide clear evidence that the gene flow between the two pheasants was consistent with the predictions of the isolation with migration model during divergence,indicating that there was long-term gene flow after the initial divergence(ca.2.2 million years ago).The data further support the occurrence of secondary contact between the parapatric populations since around 30 kya with recurrent gene flow to the present,a pattern that may have been induced by the population expansion of the Golden Pheasant in the late Pleistocene.The results of the study support the scenario of speciation between the Golden Pheasant and Lady Amherst’s Pheasant with cycles of mixing-isolation-mixing,possibly due to the dynamics of geographical context in the late Pleistocene.The two species provide a good research system as an evolutionary model for testing reinforcement selection in speciation.展开更多
基金supported by the National Natural Science Foundation of China(No.31471987)approved by College of Life Sciences,Beijing Normal University:No.CLSEAW-2013-007。
文摘Understanding speciation has long been a fundamental goal of evolutionary biology.It is widely accepted that speciation requires an interruption of gene flow to generate strong reproductive isolation between species.The mechanism of how speciation in sexually dichromatic species operates in the face of gene flow remains an open question.Two species in the genus Chrysolophus,the Golden Pheasant(C.pictus)and Lady Amherst’s Pheasant(C.amherstiae),both of which exhibit significant plumage dichromatism,are currently parapatric in southwestern China with several hybrid recordings in field.In this study,we estimated the pattern of gene flow during the speciation of the two pheasants using the Approximate Bayesian Computation(ABC)method based on data from multiple genes.Using a newly assembled de novo genome of Lady Amherst’s Pheasant and resequencing of widely distributed individuals,we reconstructed the demographic history of the two pheasants by the PSMC(pairwise sequentially Markovian coalescent)method.The results provide clear evidence that the gene flow between the two pheasants was consistent with the predictions of the isolation with migration model during divergence,indicating that there was long-term gene flow after the initial divergence(ca.2.2 million years ago).The data further support the occurrence of secondary contact between the parapatric populations since around 30 kya with recurrent gene flow to the present,a pattern that may have been induced by the population expansion of the Golden Pheasant in the late Pleistocene.The results of the study support the scenario of speciation between the Golden Pheasant and Lady Amherst’s Pheasant with cycles of mixing-isolation-mixing,possibly due to the dynamics of geographical context in the late Pleistocene.The two species provide a good research system as an evolutionary model for testing reinforcement selection in speciation.
