Evidence that Magnetic Navigation and Geomagnetic Imprinting Shape Spatial Genetic Variation in Sea Turtles
Evidence that Magnetic Navigation and Geomagnetic Imprinting Shape Spatial Genetic Variation in Sea Turtles
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DOI：
10.1016/j.cub.2018.03.022
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发表时间：
2018-04-23
期刊：
影响因子：
9.2
通讯作者：
Lohmann, Kenneth J.
中科院分区：
文献类型：
--
作者：
Brothers, J. Roger;Lohmann, Kenneth J.
群体遗传结构或空间遗传变异的典型驱动因素是距离隔离和环境隔离。距离隔离预测邻近的种群将在遗传上相似，而地理上遥远的种群将在遗传上不同[1]。环境隔离的例子也存在很多，即居住在相似环境（例如相同海拔、温度或植被）的种群即使相距较远，在遗传上也相似，而居住在不同环境的种群，即使在地理上接近，在遗传上也不同[2-4]。这些双重模型为理解人口结构提供了广泛接受的概念框架[5-8]。在这里，我们提出了另一种新颖过程的证据，我们称之为导航隔离，其中长途移民使用的导航机制影响人口结构，与距离或环境的隔离无关。具体来说，我们调查了红蠵龟 (Caretta caretta) 的种群结构 [9]，它们通过沿着海岸寻找独特的磁特征返回到出生的海滩上筑巢，这种行为称为地磁印记 [10-12]。结果表明，即使考虑到环境相似性和地理邻近性，地球磁场的空间变化也强烈预测筑巢海滩之间的遗传差异。这些发现提供了地磁印记的遗传佐证[10, 13]。此外，他们提供了强有力的证据，表明地磁印记和磁导航有助于塑造海龟的种群结构，或许还有许多其他返回出生地繁殖的长途迁徙者[13-17]。
The canonical drivers of population genetic structure, or spatial genetic variation, are isolation by distance and isolation by environment. Isolation by distance predicts that neighboring populations will be genetically similar and geographically distant populations will be genetically distinct [1]. Numerous examples also exist of isolation by environment, a phenomenon in which populations that inhabit similar environments (e.g., same elevation, temperature, or vegetation) are genetically similar even if they are distant, whereas populations that inhabit different environments are genetically distinct even when geographically close [2-4]. These dual models provide a widely accepted conceptual framework for understanding population structure [5-8]. Here, we present evidence for an additional, novel process that we call isolation by navigation, in which the navigational mechanism used by a long-distance migrant influences population structure independently of isolation by either distance or environment. Specifically, we investigated the population structure of loggerhead sea turtles (Caretta caretta) [9], which return to nest on their natal beaches by seeking out unique magnetic signatures along the coast-a behavior known as geomagnetic imprinting [10-12]. Results reveal that spatial variation in Earth's magnetic field strongly predicts genetic differentiation between nesting beaches, even when environmental similarities and geographic proximity are taken into account. The findings provide genetic corroboration of geomagnetic imprinting [10, 13]. Moreover, they provide strong evidence that geomagnetic imprinting and magnetic navigation help shape the population structure of sea turtles and perhaps numerous other long-distance migrants that return to their natal areas to reproduce [13-17].