Analysis of the Evolutionary Significance of Heterosis——taking the contribution of fitness to the genetic diversity in random mating population as an example

杂种优势的进化意义探析——以适合度对随机交配群体遗传多样性的贡献为依据(英文)

Upon the analogy of definition of heterosis and inbreeding depresstion in terms of population genetics, the heterosis is thought to be evaluated overall with fitness. By establishing a mathematical model, the equilibrium status of three genotypes of random mating population （i. e. RR, Rr and rr） under different fitness, which exposes that heterosis is the precondition for multiallele to exist in the population. The heterosis protects the genetic diversity and makes the population owning a stronger self-control and evolution potential by improving the hetemzygote＇s fithess so as not to wash out different types of genes. It deepens Darwin＇s thoughts of individual section by making the individual fitness consonant with population fitness.

学术界是从生产的角度出发理解杂种优势的，认为杂种优势就是指杂种F．代个体性状表现优于纯合基因型的情形。这实际上只是看到了杂种优势的现象，进一步分析会发现，杂种优势性状的共同点是有利于自然选择，即提高杂合子的适合度，这才是其本质。也即杂合子在穗长、穗粗、健壮等方面的优势只是适合度在性状上的表现，适合度才是基因型在自然选择中显示其生存优势的指标。该研究模型基于这一界定，使其可用数学表述，并以之为逻辑起点，