Arnaud-Haond Sophie, Moalic Yann, Hernández-García Emilio, Eguiluz Victor M, Alberto Filipe, Serrão Ester A, Duarte Carlos M
From the Ifremer, Deep-LEP, Centre de Brest, BP70, 29280 Plouzané, France (Arnaud-Haond and Moalic); the CCMAR, CIMAR-Laboratório Associado, Universidade do Algarve, Gambelas 8005-139, Faro, Portugal (Arnaud-Haond, Alberto and Serrão); the IFISC (CSIC-UIB), Instituto de Física Interdisciplinar y de Sistemas Complejos, Campus Universitat de les Illes Balears, Palma de Mallorca, Spain (Hernández-García and Eguiluz); the Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI (Alberto); the Department of Global Change Research, IMEDEA (CSIC-UIB), Instituto Mediterráneo de Estudios Avanzados, Esporles, Mallorca, Spain (Duarte); and the UWA Oceans Institute and School of Plant Biology, University of Western Australia, Crawley, Western Australia, Australia (Duarte).
J Hered. 2014 Jul-Aug;105(4):532-541. doi: 10.1093/jhered/esu015. Epub 2014 Mar 19.
The recurrent lack of isolation by distance reported at regional scale in seagrass species was recently suggested to stem from stochastic events of large-scale dispersal. We explored the usefulness of phylogenetic information contained in microsatellite loci to test this hypothesis by using the Genetic Diversity Spectrum (GDS) on databases containing, respectively, 7 and 9 microsatellites genotypes for 1541 sampling units of Posidonia oceanica and 1647 of Cymodocea nodosa The simultaneous increase of microsatellite and geographic distances that emerges reveals a coherent pattern of isolation by distance in contrast to the chaotic pattern previously described using allele frequencies, in particular, for the long-lived P. oceanica These results suggest that the lack of isolation by distance, rather than the resulting from rare events of large-scale dispersal, reflects at least for some species a stronger influence of mutation over migration at the scale of the distribution range. The global distribution of genetic polymorphism may, therefore, result predominantly from ancient events of step-by-step (re)colonization followed by local recruitment and clonal growth, rather than contemporary gene flow. The analysis of GDS appears useful to unravel the evolutionary forces influencing the dynamics and evolution at distinct temporal and spatial scales by accounting for phylogenetic information borne by microsatellites, under an appropriate mutation model. This finding adds nuance to the generalization of the influence of large-scale dispersal on the dynamics of seagrasses.
海草物种在区域尺度上反复出现的距离隔离缺失现象，最近有人认为是源于大规模扩散的随机事件。我们通过在数据库上使用遗传多样性谱（GDS），探索微卫星位点中包含的系统发育信息对检验这一假设的有用性，这些数据库分别包含1541个海洋波喜荡采样单元的7个微卫星基因型和1647个瘤状丝粉藻的9个微卫星基因型。微卫星距离和地理距离同时增加所呈现出的结果，揭示了一种与先前使用等位基因频率描述的混乱模式相反的连贯的距离隔离模式，特别是对于长寿的海洋波喜荡。这些结果表明，距离隔离缺失并非源于罕见的大规模扩散事件，至少对某些物种而言，在分布范围尺度上，突变对迁移的影响更强。因此，遗传多态性的全球分布可能主要源于逐步（重新）定殖的古老事件，随后是局部补充和克隆生长，而非当代基因流。在适当的突变模型下，通过考虑微卫星携带的系统发育信息，GDS分析似乎有助于揭示影响不同时空尺度动态和进化的进化力量。这一发现为大规模扩散对海草动态影响的普遍性增添了细微差别。
