Speciation with gene flow via cycles of isolation and migration:insights from multiple mangrove taxa

作     者：Ziwen He Xinnian Li Ming Yang Xinfeng Wang Cairong Zhong Norman C.Duke Chung-I Wu Suhua Shi Ziwen He;Xinnian Li;Ming Yang;Xinfeng Wang;Cairong Zhong;Norman C.Duke;Chung-I Wu;Suhua Shi

作者机构：State Key Laboratory of BiocontrolGuangdong Key Lab of Plant Resources Key Laboratory of Biodiversity Dynamics and Conservation of Guangdong Higher Education InstitutesSchool of Life Sciences Sun Yat-Sen University Department of Ecology and EvolutionUniversity of Chicago CAS Key Laboratory of Genome Sciences and Information Beijing Institute of GenomicsChinese Academy of Sciences Hainan Dongzhai Harbor National Nature Reserve Administration Centre for Tropical Water and Aquatic Ecosystem ResearchJames Cook University 

出 版 物：《National Science Review》 (国家科学评论(英文版))

年 卷 期：2019年第6卷第2期

页      面：275-288页

核心收录：

学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学] 

基　　金：supported by the National Natural Science Foundation of China(91731301 and 31600182) the National Key Research and Development Plan(2017FY100705) the 985 Project(33000–18831107) the Fundamental Research Funds for the Central Universities(17lgpy99) 

主　　题：speciation gene flow allopatry geographical isolation mangrove 

摘      要：Allopatric speciation requiring an unbroken period of geographical isolation has been the standard model of neo-Darwinism. While doubts have been repeatedly raised, strict allopatry without any gene flow remains a plausible mechanism in most cases. To rigorously reject strict allopatry, genomic sequences superimposed on the geological records of a well-delineated geographical barrier are necessary. The Strait of Malacca,narrowly connecting the Pacific and Indian Ocean coasts, serves at different times either as a geographical barrier or a conduit of gene flow for coastal/marine species. We surveyed 1700 plants from 29 populations of 5 common mangrove species by large-scale DNA sequencing and added several whole-genome assemblies. Speciation between the two oceans is driven by cycles of isolation and gene flow due to the fluctuations in sea level leading to the opening/closing of the Strait to ocean currents. Because the time required for speciation in mangroves is longer than the isolation phases, speciation in these mangroves has proceeded through many cycles of mixing-isolation-mixing, or MIM, cycles. The MIM mechanism, by relaxing the condition of no gene flow, can promote speciation in many more geographical features than strict allopatry can. Finally, the MIM mechanism of speciation is also efficient, potentially yielding mn(m 1) species after n cycles.