Data from: Investigating population genetic structure in a highly mobile marine organism: the minke whale Balaenoptera acutorostrata acutorostrata in the North East Atlantic

Inferring the number of genetically distinct populations and their levels
of connectivity is of key importance for the sustainable management and
conservation of wildlife. This represents an extra challenge in the marine
environment where there are few physical barriers to gene-flow, and
populations may overlap in time and space. Several studies have
investigated the population genetic structure within the North Atlantic
minke whale with contrasting results. In order to address this issue, we
analyzed ten microsatellite loci and 331 bp of the mitochondrial D-loop on
2990 whales sampled in the North East Atlantic in the period 2004 and
2007–2011. The primary findings were: (1) No spatial or temporal genetic
differentiations were observed for either class of genetic marker. (2)
mtDNA identified three distinct mitochondrial lineages without any
underlying geographical pattern. (3) Nuclear markers showed evidence of a
single panmictic population in the NE Atlantic according STRUCTURE's
highest average likelihood found at K = 1. (4) When K = 2 was accepted,
based on the Evanno's test, whales were divided into two more or less
equally sized groups that showed significant genetic differentiation
between them but without any sign of underlying geographic pattern.
However, mtDNA for these individuals did not corroborate the
differentiation. (5) In order to further evaluate the potential for
cryptic structuring, a set of 100 in silico generated panmictic
populations was examined using the same procedures as above showing
genetic differentiation between two artificially divided groups, similar
to the aforementioned observations. This demonstrates that clustering
methods may spuriously reveal cryptic genetic structure. Based upon these
data, we find no evidence to support the existence of spatial or cryptic
population genetic structure of minke whales within the NE Atlantic.
However, in order to conclusively evaluate population structure within
this highly mobile species, more markers will be required.

推断遗传分化种群的数量及其连通性水平，对于野生动物的可持续管理与保护具有核心意义。这在海洋环境中尤具挑战：海洋中阻碍基因流的物理屏障极少，且种群可能在时间与空间上存在重叠。已有多项研究针对北大西洋小须鲸的种群遗传结构展开分析，但所得结果存在分歧。
为解决这一问题，本研究对2004年及2007—2011年在东北大西洋海域采集的2990份小须鲸样本，开展了10个微卫星位点（microsatellite loci）与331个碱基对（base pair, bp）长度的线粒体D环（mitochondrial D-loop）序列分析。
主要研究结果如下：(1) 两类遗传标记均未检测到空间或时间维度上的遗传分化。(2) 线粒体DNA（mitochondrial DNA, mtDNA）分析显示存在3个独立的线粒体谱系，但未呈现任何潜在的地理分布模式。(3) 根据STRUCTURE软件在K=1时得到的最高平均似然值，核标记结果显示东北大西洋海域存在单一泛交种群。(4) 基于埃瓦诺检验（Evanno's test）选取K=2时，样本被划分为两个规模大致相当的类群，二者间存在显著遗传分化，但未呈现任何潜在地理分布模式；然而对应个体的线粒体DNA分析结果并未验证这一分化。(5) 为进一步评估隐秘种群结构存在的可能性，本研究采用上述分析流程，对100组计算机模拟（in silico）生成的泛交种群开展检验，结果在人工划分的两个类群间检测到了遗传分化，与前述观测结果类似。这表明聚类方法可能会虚假检出本不存在的隐秘遗传结构。
基于上述数据，本研究未发现证据支持东北大西洋海域小须鲸存在空间或隐秘种群遗传结构。但要对这一高度洄游物种的种群结构做出定论性评估，仍需更多遗传标记的支持。