Department of Zoology, Edward Grey Institute, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom.
Evolution. 2010 May;64(5):1202-17. doi: 10.1111/j.1558-5646.2010.00966.x. Epub 2010 Feb 9.
Owing to the remarkable progress of molecular techniques, heterozygosity-fitness correlations (HFCs) have become a popular tool to study the impact of inbreeding in natural populations. However, their underlying mechanisms are often hotly debated. Here we argue that these "debates" rely on verbal arguments with no basis in existing theory and inappropriate statistical testing, and that it is time to reconcile HFC with its historical and theoretical fundaments. We show that available data are quantitatively and qualitatively consistent with inbreeding-based theory. HFC can be used to estimate the impact of inbreeding in populations, although such estimates are bound to be imprecise, especially when inbreeding is weak. Contrary to common belief, linkage disequilibrium is not an alternative to inbreeding, but rather comes with some forms of inbreeding, and is not restricted to closely linked loci. Finally, the contribution of local chromosomal effects to HFC, while predicted by inbreeding theory, is expected to be small, and has rarely if ever proven statistically significant using adequate tests. We provide guidelines to safely interpret and quantify HFCs, and present how HFCs can be used to quantify inbreeding load and unravel the structure of natural populations.
由于分子技术的显著进步，杂合度-适合度相关性（HFCs）已成为研究自然种群中近交影响的流行工具。然而，其潜在机制经常存在激烈的争论。在这里，我们认为这些“争论”依赖于没有现有理论基础和不适当的统计检验的口头争论，现在是时候将 HFC 与其历史和理论基础协调一致了。我们表明，现有数据在定量和定性上与基于近交的理论一致。HFC 可用于估计种群中的近交影响，尽管这种估计必然不精确，尤其是当近交较弱时。与普遍看法相反，连锁不平衡不是近交的替代品，而是与某些形式的近交有关，并且不限于紧密连锁的基因座。最后，虽然近交理论预测了局部染色体效应对 HFC 的贡献，但预计其贡献很小，并且使用适当的测试很少甚至从未证明具有统计学意义。我们提供了安全解释和量化 HFC 的指南，并展示了如何使用 HFC 量化近交负荷并揭示自然种群的结构。
