Data from: Comparative tests of the species-genetic diversity correlation at neutral and non-neutral loci in four species of stream insect

A fundamental question linking population genetics and community ecology is how adaptive processes (e.g., natural selection) and neutral processes (e.g., drift-migration equilibrium) underpin the species-genetic diversity correlation (SGDC). Here we combine genome scans and outlier loci detection with community analysis to separately test for neutral and non-neutral SGDCs in four species of stream insect. We sampled 60 localities in Japan and examined the relationships among population AFLP band richness (<i>Br</i>), taxon richness of the total community (<i>S</i>) and of the trophic guild (<i>S</i>_tr) richness, and 15 habitat parameters that could potentially drive adaptation and influence richness. Neutral <i>Br</i> was positively correlated with <i>S</i> only in the dominant species of these communities, suggesting <i>Br</i> may be constrained when intra-specific competition is pronounced. Non-neutral <i>Br</i> was correlated with <i>S</i>_tr in a species restricted to high elevations where habitat heterogeneity was highest. Community distance and genetic distance (β-SGDC) was correlated in two of the four species at both neutral and non-neutral loci. Distance-based redundancy analysis found geographic isolation and elevation to drive divergence of both communities and populations. This suggests that both neutral and adaptive divergence occurred through the shared influences of geographic isolation and local adaptation at the two levels of diversity.

将种群遗传学与群落生态学联系起来的核心科学问题之一，是适应性过程（如自然选择）与中性过程（如漂变-迁移平衡）如何支撑物种-遗传多样性相关性（species-genetic diversity correlation, SGDC）。本研究将基因组扫描、异常位点检测与群落分析相结合，分别检验了4种溪流昆虫中中性与非中性的SGDC。我们在日本境内布设了60个采样点，分析了种群扩增片段长度多态性（Amplified Fragment Length Polymorphism, AFLP）条带丰富度（Br）、总群落分类单元丰富度（S）、营养功能群分类单元丰富度（S_tr）与15种潜在驱动适应性过程并影响丰富度的生境参数之间的关联。仅在这些群落的优势物种中，中性Br才与S呈显著正相关，这表明当种内竞争加剧时，Br可能会受到限制。在仅分布于生境异质性最高的高海拔区域的某一物种中，非中性Br与S_tr呈显著相关。在中性与非中性位点上，4个物种中的2个物种的群落距离与遗传距离（β-SGDC）均呈显著相关。基于距离的冗余分析结果显示，地理隔离与海拔驱动了群落与种群的分化。这表明，在两个多样性层级上，中性分化与适应性分化均受到地理隔离与局部适应的共同影响。