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The geography of introgression in a patchy environment and the thorn in the side of ecological speciation

Current Zoology 2013年第1期59卷 72-86页

作者： Nicolas BIERNE pierre-alexandre gagnaire Patrice DAVID Universit6 Montpellier 2 Place Eugene Bataillon 34095 Montpellier Cedex 5 France ISEM - CNRS UMR 5554 SMEL 2 rue des Chantiers 34200 S6te France CEFE - CNRS UMR 5175 34293 MontpeUier Cedex 5 France

When incompletely isolated taxa coexist in a patchy environment （e.g. mosaic hybrid zones, host-race complexes）, patterns of variation may differ between selected traits/genes and neutral markers. While the genetic structure of selected traits/loci tends to coincide with habitat variables （producing Genetic-Environment Association or GEA）, genetic differentiation at neutral loci unlinked to any selected locus rather depends on geographic connectivity at a large scale （e.g. Isolation- By-Distance or IBD）, although these loci often display GEA at a small scale. This discrepancy has been repeatedly taken as evi- dence for parallel primary divergence driven by local adaptation. We argue that this interpretation needs to be addressed more thoroughly by considering the alternative hypothesis that speciation was initiated in allopatry and secondary introgression has subsequently erased the signal of past differentiation at neutral loci. We present a model of neutral introgression after secondary contact in a mosaic hybrid zone, which describes how GEAs dissipate with time and how neutral variation self-organizes accord- ing to the environmental and geographic structures. We show that although neutral loci can be affected by environmental selection they are often more affected by history and connectivity： the neutral structure retains the initial geographic separation more than it correlates with the environment during the colonization and introgression phases, and then converges to a migration-drift balance, the most frequent outcome of which is GEA at a local scale but IBD at a large scale. This is the exact pattern usually attributed to parallel ecological speciation. Introgression is heterogeneous in space and depends on the landscape structure （e.g. it is faster in small patches, which are more impacted by immigration）. Furthermore, there is no directionality in the association and it is possi- ble to observe reversed GEAs between distant regions. We argue that the his

关键词： Ecological speciation Local adaptation Mosaic hybrid zone Reproductive isolation Genetic-environment association

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Detecting polygenic selection in marine populations by combining population genomics and quantitative genetics approaches

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Current Zoology 2016年第6期62卷 603-616页

作者： pierre-alexandre gagnaire Oscar E. GAGGIOTTI Universite Montpellier 2 Place Eugene Bataillon 34095 Montpellier Cedex 5 France ISEM - CNRS UMR 5554 SMEL 2 rue des Chantiers Sete 34200 France Scottish Oceans Institute University of St Andrews East Sands St Andrews KY16 9LB UK

Highly fecund marine species with dispersive life-history stages often display large population sizes and wide geographic distribution ranges. Consequently, they are expected to experience reduced genetic drift, efficient selection fueled by frequent adaptive mutations, and high migration loads. This has important consequences for understanding how local adaptation proceeds in the sea. A key issue in this regard, relates to the genetic architecture underlying fitness traits. Theory predicts that adaptation may involve many genes but with a high variance in effect size. Therefore, the effect of selection on allele frequencies may be substantial for the largest effect size loci, but insignificant for small effect genes. In such a context, the performance of population genomic methods to unravel the genetic basis of adaptation depends on the fraction of adaptive genetic variance explained by the cumulative effect of outlier loci. Here, we address some methodological challenges associated with the detection of local adaptation using molecular approaches. We provide an overview of genome scan methods to detect selection, including those assuming complex demographic models that better describe spatial population structure. We then focus on quantitative genetics approaches that search for genotype-phenotype associations at different genomic scales, including genome-wide methods evaluating the cumulative effect of variants. We argue that the limited power of single locus tests can be alleviated by the use of polygenic scores to estimate the joint contribution of candidate variants to phenotypic variation.

关键词： local adaptation genome scans quantitative genetics genotype-phenotype association polygenic scores.

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法国国防部大楼——自我循环的生态机器

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城市环境设计 2015年第8期 72-81页

作者： Michel Delplace Cyril Trétout Jean-pierre Buisson Simon Barthélémy Cecilia Bertozzi Henry gagnaire Gérald Sellier Agence Nicolas Michelin & Associés-ANMA Nicolas Michelin

项目名称:法国国防部大楼项目地点:法国巴黎建筑面积:165 000m2竞赛时间:2009.09-2011.01设计时间:2011.05-2011.09建成时间:2015新法国国防部是目前巴黎大区最大的工地:16架吊车夜不停息地运作,两个混凝土制造中心每天生产高达500m3的... 详细信息

项目名称:法国国防部大楼项目地点:法国巴黎建筑面积:165 000m2竞赛时间:2009.09-2011.01设计时间:2011.05-2011.09建成时间:2015新法国国防部是目前巴黎大区最大的工地:16架吊车夜不停息地运作,两个混凝土制造中心每天生产高达500m3的混凝土,一个10 000m2规模的生活区供2 000名工人使用。这里正在创造着8hm2的立面和巴黎最大的太阳能屋面。这正是位于巴黎十五区的由ANMA事务所主持设计的国防部大楼的施工现场,这里将拥有一个可供9 300名军人和市民同时使用的14hm2的办公区和一个9 300m2的公共设施。

关键词：国防部自我循环办公建筑机器法国法兰西共和国

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