Hill W G, Mbaga S H
Institute of Cell, Animal and Population Biology, University of Edinburgh, Scotland.
Genetica. 1998;102-103(1-6):171-81.
There is substantial new variation for quantitative traits generated by mutation that can be utilised by artificial selection. With long-term selection, however, response is often attenuated and a selection limit sometimes reached, even though genetic variation is frequently still present in these lines. In this paper, the theoretical bases of long-term response and variability of populations that come from mutational variance are reviewed, and the relation between them is related to the strength and mode of the natural selection, whether due to pleiotropic effects of mutant genes or stabilising selection. Simple formulae to predict the consequence of relaxed or reversed selection are derived. Results from long-term selection experiments in mice in this laboratory are described and related to the theoretical analyses with the aim of reconciling the evidence for substantial standing variation with the low rate of response.
由突变产生的数量性状存在大量新的变异，可被人工选择利用。然而，经过长期选择，即使这些品系中通常仍存在遗传变异，反应往往会减弱，有时还会达到选择极限。本文回顾了来自突变方差的群体长期反应和变异性的理论基础，并将它们之间的关系与自然选择的强度和模式联系起来，无论这种自然选择是由于突变基因的多效性效应还是稳定选择所致。推导了预测放松或反向选择后果的简单公式。描述了本实验室小鼠长期选择实验的结果，并将其与理论分析相关联，目的是协调大量现存变异的证据与低反应率之间的矛盾。
