A STUDY OF REACTION NORMS IN NATURAL-POPULATIONS OF DROSOPHILA-PSEUDOOBSCURA
A STUDY OF REACTION NORMS IN NATURAL-POPULATIONS OF DROSOPHILA-PSEUDOOBSCURA
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DOI：
10.1111/j.1558-5646.1982.tb05464.x
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发表时间：
1982-01-01
期刊：
影响因子：
3.3
通讯作者：
LEWONTIN, RC
中科院分区：
文献类型：
--
作者：
GUPTA, AP;LEWONTIN, RC
本文研究了来自三个不同自然群体的32个第二染色体同染色体品系及其杂合体的刚毛数、生活力和发育时间的反应规范。在2种卵密度和3种温度下，虽然基因型、温度和密度的效应都很平均，但基因型与环境的互作效应很大。也就是说，在1个温度下具有最高刚毛数或最快发育的基因型在其他温度下没有保持其与其他品系的差异。约30-45%的基因型间的成对比较显示，温度变化时，相对位置的实际逆转。不可能将一个基因型描述为比另一个基因型具有更高的刚毛数量或更快的发育，因为这只能与给定的环境相关。自然发生的基因型在这方面不同于经典突变体，后者在某些环境中可能与野生型重叠，但总是与正常突变体至少在一个方向上不同。因此，从实验室突变体推断发育行为是错误的。证据也提出，不知道规范的反应，目前的环境分布，目前的基因型分布，并没有然后指定哪些环境和哪些基因型是固定或消除，这是不可能预测的总变异是否会增加，减少，或保持不变的环境或遗传的变化，或自然选择的结果会是什么。
A study of the reaction norms on the number of bristles, viability and development time is presented for 32 strains isochromosomal for the 2nd chromosome and their heterozygotes from 3 different natural populations of D. pseudoobscura, at 2 egg densities and 3 temperatures. Although there were average effects of genotype, temperature and density, there were very large genotype-environment interaction effects. That is, the genotype with the highest bristle number or fastest development at 1 temperature did not maintain its difference from other lines at other temperatures. About 30-45% of pairwise comparisons between genotypes showed actual reversals in relative position when temperature was changed. It is not possible to characterize a genotype as having a higher bristle number or faster development than another, since this can only be relative to a given environment. Naturally occurring genotypes differ in this respect from classical mutants which may overlap wild types in some environments but always vary at least in 1 direction from normal. It is, therefore, a mistake to infer the developmental behavior from laboratory mutants. Evidence is also presented that without knowing the norms of reaction, the present distribution of environments, the present distribution of genotypes, and without then specifying which environments and which genotypes are to be fixed or eliminated, it is impossible to predict whether the total variation would be increased, decreased, or remain unchanged by environmental or genetic changes, or what the outcome of natural selection would be.