Clarke B C
Proc R Soc Lond B Biol Sci. 1979 Sep 21;205(1161):453-74. doi: 10.1098/rspb.1979.0079.
The existence within natural populations of large amounts of genetic variation in molecules and morphology presents an evolutionary problem. The 'neutralist' solution to this problem, that the variation is usually unimportant to the organism displaying it, has now lost much of its strength. Interpretations that assume widespread heterozygous advantage also face serious difficulties. A resolution is possible in terms of frequency-dependent selection by predators, parasites and competitors. The evidence for pervasive frequency-dependent selection is now very strong. It appears to follow naturally from the behaviour of predators, from the evolutionary lability of parasites, from the ecology of competition and, at the molecular level, from the phenomena of enzyme kinetics. Such selection can explain the maintenance not only of conventional polymorphism but also of continuous variation in both molecular and morphological characters. It can account for the occurrence of diversity within groups of haploid and self-fertilizing organisms, and for the evolution of differences between individuals in their systems of genetic control.
自然种群中在分子和形态上存在大量遗传变异，这提出了一个进化问题。对于这个问题的“中性论”解决方案，即这种变异通常对表现出它的生物体不重要，现在已经失去了很多说服力。假设广泛存在杂合优势的解释也面临严重困难。从捕食者、寄生虫和竞争者的频率依赖选择角度来看，找到解决方案是有可能的。现在有非常有力的证据表明普遍存在频率依赖选择。它似乎自然地源于捕食者的行为、寄生虫的进化易变性、竞争生态学，以及在分子水平上源于酶动力学现象。这种选择不仅可以解释传统多态性的维持，还能解释分子和形态特征的连续变异。它可以解释单倍体和自交生物群体内多样性的出现，以及个体在遗传控制系统方面差异的进化。
