Quantitative Genetics in the Wild
Quantitative Genetics in the Wild
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野外定量遗传学
DOI：
10.1093/acprof:oso/9780199674237.003.0010
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Kruuk L
中科院分区：
文献类型：
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作者：
Kruuk L
当前进化数量遗传学的一个中心问题是如何解释在选择的侵蚀效应面前丰富的遗传变异的维持（罗夫1997;沃尔什和Blows 2009）。一个相关的问题是，我们也不明白为什么观察到的进化对选择的反应经常与预测不符（Merilä et al. 2001;沃尔什& Blows 2009）。这两个问题可能有共同的解释：例如，可能是遗传变异与选择的多元方向不一致（Blows & Hoffmann 2005），或者，感兴趣的表型性状不会因果地影响适合度，而只是由于性状和适合度与环境诱导的条件方面的关联而似乎处于选择之下。（Price et al. 1988; Rausher 1992）。在这种情况下，不会发生对选择的进化反应，从而防止了表型特征的遗传变异的丧失。检验这些假说涉及探索表型变异的遗传结构。动物育种的统计学定量遗传学工具在这方面起了关键作用，并促进了自然种群研究的许多最新活动，本书中的章节就是明证。然而，这项工作最终强调了上述悖论，反复提供了丰富的遗传变异，强定向选择和自然种群中明显的微进化停滞的证据（Merilä et al. 2001; Kruuk et al. 2008）。为了调和这些矛盾，我们现在需要将选择过程的联合收割机分析与数量遗传模型结合起来。这样做的能力受到进化数量遗传学领域最近几项发展的推动，我们在下面概述;然后，我们用野生有蹄类动物种群中性选择武器的分析来说明这些。第一个动机是越来越多的人认识到定量遗传分析与选择研究的相关性，特别是需要考虑变异和共变异的遗传原因而不仅仅是表型原因。当考虑性状之间的关系时，表型关联与遗传关联不同（Hadfield 2008; Kruuk et al. 2008）。两者之间的差异在自然环境中的野生种群中可能特别明显，在受控环境中经历比人工种群更大的环境变化，并且当考虑两个性状之间的关联时，其中一个是适合度的估计，即考虑选择压力时。这种差异的含义的一个清楚的说明是，
A central problem in current evolutionary quantitative genetics is how to explain the maintenance of abundant genetic variance in the face of the eroding effects of selection (Roff 1997; Walsh & Blows 2009). A related problem is that we also do not understand why observed evolutionary responses to selection frequently fail to match predictions (Merilä et al. 2001; Walsh & Blows 2009). These two issues may have common explanations: for example, it may be that genetic variation is not aligned with the multivariate direction of selection (Blows & Hoffmann 2005), or alternatively, that the phenotypic traits of interest do not causally affect fitness but only appear to be under selection because of associations of both trait and fitness with environmentally induced aspects of condition (Price et al. 1988; Rausher 1992). Under such scenarios, no evolutionary response to selection will occur, thus preventing the loss of genetic variation underlying phenotypic traits. Testing these hypotheses involves exploration of the genetic architecture underlying phenotypic variation. The statistical quantitative genetic tools of animal breeding have been critical for this and have facilitated much recent activity in studies of natural populations, as evidenced by the chapters in this book. However this work has ultimately served to underline the above paradoxes, repeatedly providing evidence of abundant genetic variation, strong directional selection and yet apparent microevolutionary stasis in natural populations (Merilä et al. 2001; Kruuk et al. 2008). To reconcile these inconsistencies, we now need to combine analyses of the process of selection with quantitative genetic models. The ability to do so has been motivated by several recent developments in the field of evolutionary quantitative genetics, which we outline below; we then illustrate these with an analysis of sexually selected weaponry in a wild ungulate population.The first motivation is the increasing appreciation of the relevance of quantitative genetic analyses to studies of selection, and in particular of the need to consider the genetic rather than just the phenotypic causes of variation and covariation. When considering relationships amongst traits, phenotypic associations are not the same as genetic ones (Hadfield 2008; Kruuk et al. 2008). The difference between the two may be especially apparent in wild populations in natural environments, experiencing greater environmental variation than artificial populations in controlled environments, and also when considering the association between two traits where one is an estimate of fitness, ie when considering selection pressures. A clear illustration of the implication of this difference comes