The Effect of Variation of Fitness
The Effect of Variation of Fitness
复制标题
健身变化的影响
作者：
American Naturalist;Lxxi July;B. S. Haldane;John Innes
在一个平衡的物种中，变异主要是由于两个原因。一些有害基因正以与突变产生的速度一样的速度被自然选择淘汰。另一些则被保留下来，因为杂合子的形式比纯合子的形式更适合。在前一种情况下，物种适应性的损失大致等于所有突变率的总和，可能为5%，这表明适应性的损失是物种为进一步进化的能力所付出的代价。
In a species in equilibrium variation is mainly due to two causes. Some deleterious genes are being weeded out by selection at the same rate as they are produced by mutation. Others are preserved because the heterozygous form is fitter than either homozygote. In the former case the loss of fitness in the species is roughly equal to the sum of all mutation rates and is probably of the order of 5 per cent. It is suggested that this loss of fitness is the price paid by a species for its capacity for further evolution.