Hereford Joe
National Evolutionary Synthesis Center, Durham, North Carolina 27705, USA.
Am Nat. 2009 May;173(5):579-88. doi: 10.1086/597611.
The long history of reciprocal transplant studies testing the hypothesis of local adaptation has shown that populations are often adapted to their local environments. Yet many studies have not demonstrated local adaptation, suggesting that sometimes native populations are no better adapted than are genotypes from foreign environments. Local adaptation may also lead to trade-offs, in which adaptation to one environment comes at a cost of adaptation to another environment. I conducted a survey of published studies of local adaptation to quantify its frequency and magnitude and the costs associated with local adaptation. I also quantified the relationship between local adaptation and environmental differences and the relationship between local adaptation and phenotypic divergence. The overall frequency of local adaptation was 0.71, and the magnitude of the native population advantage in relative fitness was 45%. Divergence between home site environments was positively associated with the magnitude of local adaptation, but phenotypic divergence was not. I found a small negative correlation between a population's relative fitness in its native environment and its fitness in a foreign environment, indicating weak trade-offs associated with local adaptation. These results suggest that populations are often locally adapted but stochastic processes such as genetic drift may limit the efficacy of divergent selection.
长期以来，针对局部适应性假说开展的相互移植研究表明，种群通常会适应其当地环境。然而，许多研究并未证明存在局部适应性，这表明有时本地种群并不比来自其他环境的基因型更具适应性。局部适应性也可能导致权衡取舍，即适应一种环境是以牺牲对另一种环境的适应能力为代价的。我对已发表的局部适应性研究进行了一项调查，以量化其频率和程度以及与局部适应性相关的代价。我还量化了局部适应性与环境差异之间的关系以及局部适应性与表型差异之间的关系。局部适应性的总体频率为0.71，本地种群在相对适合度方面的优势程度为45%。原生地环境之间的差异与局部适应性的程度呈正相关，但与表型差异无关。我发现一个种群在其原生环境中的相对适合度与其在其他环境中的适合度之间存在微弱的负相关，这表明与局部适应性相关的权衡取舍较弱。这些结果表明，种群通常具有局部适应性，但诸如遗传漂变等随机过程可能会限制分化选择的效力。
