Divergence between Antarctic and South American marine invertebrates: What molecular biology tells us about Scotia Arc geodynamics and the intensification of the Antarctic Circumpolar Current
Divergence between Antarctic and South American marine invertebrates: What molecular biology tells us about Scotia Arc geodynamics and the intensification of the Antarctic Circumpolar Current
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南极和南美海洋无脊椎动物之间的分歧：分子生物学告诉我们有关斯科舍岛弧地球动力学和南极绕极流增强的信息
DOI：
10.1016/j.gloplacha.2014.07.017
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发表时间：
2014
影响因子：
3.9
通讯作者：
M. Hüne
中科院分区：
文献类型：
--
作者：
E. Poulin;C. González‐Wevar;A. Díaz;K. Gérard;M. Hüne
大陆漂移过程，如主要的门户开口历来主张解释海洋底栖生物类群在南大洋（SO）的分布。南极半岛与南美洲南端的分离以及南极绕极流（ACC）的出现标志着南极地区走向完全孤立的最后一步。然而，关于这一过程的时间和模式，特别是关于斯科舍弧地球动力学在发展一个完全深层和强化的ACC环流中的作用，仍然存在争议。基于从不同类群获得的线粒体细胞色素c氧化酶亚基I（COI）序列，我们进行了南极洲和南美亲属之间的分子比较，以提供独立的时间估计南极洲的隔离。我们在分析中包括同源南极和巴塔哥尼亚近岸海洋底栖无脊椎动物，包括间接开发商（Nacella，Yoldia，Sterechinus，和Parbolasia）和育雏（XyabelsisandTrophonella）。考虑到这两个地区的亲属之间的遗传分化水平，并假设分子钟假说，我们估计了各自的分歧的开始。一方面，广播产卵者（7%-8.3%）的遗传距离相似的水平支持这一假设，即南极洲和南美洲之间的有效屏障的发展几乎同时发生这些群体。基于特定替代率的分歧时间估计表明，分离发生在中新世-上新世过渡期附近，在两个大陆物理分离之后很久。遗传距离和分歧的时间估计在直接开发表明一个老的分离时间，接近中新世中期。即使当分析的群体包括广播产卵和育雏生物，南极和南美洲血统之间的分歧，而不是相关的大陆漂移过程，似乎更多地与南大洋的重大变化，如斯科舍弧的演变和德雷克海峡的加深。因此，这些结果支持南极洲和南美洲之间的遗传连续性，可能沿着斯科舍海脊，直到中新世中期和晚ACC在中新世-上新世边界的加强。
Continental drift processes such as major gateway openings have been historically advocated to explain the distribution of marine benthic taxa in the Southern Ocean (SO). The separation between Antarctic Peninsula and the southern tip of South America together with the onset of the Antarctic Circumpolar Current (ACC) represent the final step for the complete isolation of the Antarctic region. However, there is still controversy concerning the timing and mode of this process, and especially about the role of the Scotia Arc geodynamics in the development of a fully deep and intensified ACC circulation. Based on mitochondrial Cytochrome c Oxidase Subunit I (COI) sequences obtained from different taxa, we performed molecular comparisons between Antarctic and South American relatives to provide independent time estimations of Antarctica's isolation. We include in the analyses congeneric Antarctic and Patagonian near-shore marine benthic invertebrates including indirect developers (Nacella,Yoldia,Sterechinus, andParbolasia) and brooders (XymenopsisandTrophonella). Considering the levels of genetic differentiation between relatives from both regions and assuming the molecular clock hypothesis, we estimated the onset of their respective divergence. On one hand, similar levels of genetic distance in broadcast–spawners (7%–8.3%) support the hypothesis that the development of an effective barrier between Antarctica and South America occurred almost simultaneously for these groups. Divergence time estimations based on specific substitution rates indicate that the separation occurred near the Mio-Pliocene transition, long after the physical separation of both continents. Genetic distance and divergence time estimation in direct developers indicate an older separation time, close to the mid-Miocene. Even when the analyzed groups included both broadcast–spawners and brooder organisms, the divergence between Antarctic and South America lineages rather than being related to processes of continental drift, seems to be associated more to major changes in the Southern Ocean such as the evolution of the Scotia Arc and the deepening of the Drake Passage. Accordingly, these results support a genetic continuity between Antarctica and South America, probably along the Scotia Ridge, until the middle Miocene and a late ACC intensification at the Mio-Pliocene boundary.
影响因子：
4
作者：
Gersonde, R;Crosta, X;Armand, L
通讯作者：
Armand, L
影响因子：
--
作者：
F. Leese;Shobhit Agrawal;C. Held
通讯作者：
F. Leese;Shobhit Agrawal;C. Held