PDF(Pubmed)
Abstract：
Genetic diversity is a fundamental component of biodiversity. Examination of global patterns of genetic diversity can help highlight mechanisms underlying species diversity, though a recurring challenge has been that patterns may vary by molecular marker. Here, we compiled 6862 observations of genetic diversity from 492 species of marine fish and tested among hypotheses for diversity gradients: the founder effect hypothesis, the kinetic energy hypothesis, and the productivity-diversity hypothesis. We fit generalized linear mixed effect models (GLMMs) and explored the extent to which various macroecological drivers (latitude, longitude, temperature (SST), and chlorophyll-a concentration) explained variation in genetic diversity. We found that mitochondrial genetic diversity followed geographic gradients similar to those of species diversity, being highest near the Equator, particularly in the Coral Triangle, while nuclear genetic diversity did not follow clear geographic patterns. Despite these differences, all genetic diversity metrics were correlated with chlorophyll-a concentration, while mitochondrial diversity was also positively associated with SST. Our results provide support for the kinetic energy hypothesis, which predicts that elevated mutation rates at higher temperatures increase mitochondrial but not necessarily nuclear diversity, and the productivity-diversity hypothesis, which posits that resource-rich regions support larger populations with greater genetic diversity. Overall, these findings reveal how environmental variables can influence mutation rates and genetic drift in the ocean, caution against using mitochondrial macrogenetic patterns as proxies for whole-genome diversity, and aid in defining global gradients of genetic diversity.
摘要：
遗传多样性是生物多样性的基本组成部分。对全球遗传多样性模式的检查可以帮助突出物种多样性的潜在机制，尽管反复出现的挑战是模式可能因分子标记而异。这里,我们从492种海鱼中收集了6862种遗传多样性的观察结果，并在多样性梯度的假设中进行了测试：创始人效应假设，动能假说,和生产力多样性假说。我们拟合了广义线性混合效应模型(GLMMs)，并探索了各种宏观生态驱动因素(纬度，经度,温度(SST),和叶绿素a浓度）解释了遗传多样性的变化。我们发现线粒体遗传多样性遵循与物种多样性相似的地理梯度，在赤道附近最高，特别是在珊瑚三角，而核遗传多样性没有遵循明确的地理模式。尽管存在这些差异,所有遗传多样性指标均与叶绿素a浓度相关，而线粒体多样性也与SST呈正相关。我们的结果为动能假说提供了支持，预测在较高温度下突变率的升高会增加线粒体，但不一定会增加核多样性，和生产力多样性假说，这表明资源丰富的地区支持具有更大遗传多样性的更大种群。总的来说,这些发现揭示了环境变量如何影响海洋中的突变率和遗传漂移，警惕使用线粒体宏观遗传模式作为全基因组多样性的代理，并帮助定义遗传多样性的全球梯度。
