Barrett Rowan D H, Schluter Dolph
Department of Zoology and Biodiversity Research Centre, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4, Canada.
Trends Ecol Evol. 2008 Jan;23(1):38-44. doi: 10.1016/j.tree.2007.09.008. Epub 2007 Nov 14.
Populations adapt to novel environments in two distinct ways: selection on pre-existing genetic variation and selection on new mutations. These alternative sources of beneficial alleles can result in different evolutionary dynamics and distinct genetic outcomes. Compared with new mutations, adaptation from standing genetic variation is likely to lead to faster evolution, the fixation of more alleles of small effect and the spread of more recessive alleles. There is potential to distinguish between adaptation from standing variation and that from new mutations by differences in the genomic signature of selection. Here we review these approaches and possible examples of adaptation from standing variation in natural populations. Understanding how the source of genetic variation affects adaptation will be integral for predicting how populations will respond to changing environments.
对已有的遗传变异进行选择以及对新突变进行选择。这些有益等位基因的不同来源可导致不同的进化动态和独特的遗传结果。与新突变相比，从现存遗传变异中产生的适应可能会导致更快的进化、更多小效应等位基因的固定以及更多隐性等位基因的传播。有可能通过选择的基因组特征差异来区分从现存变异中产生的适应和从新突变中产生的适应。在此，我们综述这些方法以及自然种群中从现存变异产生适应的可能实例。理解遗传变异的来源如何影响适应对于预测种群将如何应对不断变化的环境至关重要。
