Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland.
Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland.
Mol Phylogenet Evol. 2018 Oct;127:613-625. doi: 10.1016/j.ympev.2018.06.008. Epub 2018 Jun 12.
Stickleback fishes in the family Gasterosteidae have become model organisms in ecology and evolutionary biology. However, even in the case of the most widely studied species in this family - the three-spined stickleback (Gasterosteus aculeatus) - the worldwide phylogenetic relationships and colonization history of the different populations and lineages remain poorly resolved. Using a large collection of samples covering most parts of the species distribution range, we subjected thousands of single nucleotide polymorphisms to coalescent analyses in order to reconstruct a robust worldwide phylogeny of extant G. aculeatus populations, as well as their ancestral geographic distributions using Statistical-Dispersal Vicariance and Bayesian Binary MCMC analyses. The results suggest that contemporary populations originated from the Pacific Ocean in the Late Pleistocene, and the Atlantic was colonized through the Arctic Ocean by a lineage that diverged from Pacific sticklebacks ca 44.6 Kya. This lineage contains two branches: one that is distributed in the Mediterranean area, from the Iberian Peninsula to the Black Sea ('Southern European Clade'), and another that is comprised of populations from northern Europe and the east coast of North America ('Trans-Atlantic Clade'). Hence, the results suggest that the North American East Coast was colonized by trans-Atlantic migration. Coalescence-based divergence time estimates suggest that divergence among major clades is much more recent than previously estimated.
棘鱼科的棘鱼属鱼类已成为生态学和进化生物学的模式生物。然而，即使在这个科中最广泛研究的物种——三刺棘鱼（Gasterosteus aculeatus）中，不同种群和谱系的全球系统发育关系和殖民历史仍然没有得到很好的解决。我们使用了一个包含了大多数物种分布范围的样本的大型收集，对数千个单核苷酸多态性进行了合并分析，以便重建现存的三刺棘鱼种群的稳健全球系统发育，以及使用统计-扩散分歧和贝叶斯二元 MCMC 分析来重建它们的祖先地理分布。结果表明，当代种群起源于更新世晚期的太平洋，而大西洋是通过一条从太平洋棘鱼分化出来的谱系通过北冰洋殖民的，这条谱系分化于 44.6 千年前。这个谱系包含两个分支：一个分布在地中海地区，从伊比利亚半岛到黑海（“南欧支系”），另一个由北欧和北美东海岸的种群组成（“跨大西洋支系”）。因此，结果表明，北美东海岸是通过跨大西洋迁徙而被殖民的。基于合并的分歧时间估计表明，主要支系之间的分歧比以前估计的要近得多。
