1.The concept of molecular evolution(分子进化的概念)
Molecular evolution is the branchof evolution that analyses biological molecular differences, mainly inDNA, RNA or protein sequences, to gain information on an organism'sevolutionary relationships. (分子进化是各种生物大分子如DNA、RNA、蛋白质的演变以及这些变化与生物进化的关系。分子进化是进化学的一门分支。)
2.Neutral Theory of Molecular Evolution (分子进化中性学说)
The neutral theory of molecular evolution holdsthat at the molecular level most evolutionary changes and most of thevariation within and between species is not caused by natural selectionbut by genetic drift of mutant alleles that areneutral. (在分子水平上,生物的进化主要是中性突变在自然群体中进行随机的“遗传漂变”的结果,而与选择无关。)
3.Neutral Mutation(中性突变)
A neutral mutation inferredthe mutation that does not affect the ability to survive and reproduce of anorganism,that is to say, themutation is not beneficial nor deleterious, that’s why natural selection doesnot work for them.(所谓中性突变是指突变不会影响生物机体的生活力和生殖力,也就说,突变没有有利和有害之分,因此自然选择对其不起作用。
4. Genetic Drift (遗传漂变))
GeneticDrift (also known as Allelic Drift or Random genetic drift ) isthe change in the frequency of a gene allele in a population,especially a small population, due to random sampling of organisms. Geneticdrift is the basic driving force for molecular evolution.(遗传漂变是指由于某种随机因素,某一等位基因的频率在群体(尤其是小群体)中出现世代传递的波动现象,是分子进化的基本动力。)
5.Founder Effect (建立者效应)
The FounderEffect is the loss of genetic variation that occurs when a newpopulation is established by a very small number of individuals from a largerpopulation.(一些异常基因频率在小隔离群体中特别高,可能是由于该群体中少数始祖所具有的基因由于遗传漂变而逐渐达到较高的水平。)
6.molecular clock (分子钟)
The neutraltheory holds that the rate of a neutral mutation is equal to that of themolecular evolution, and for every given protein, the rate of molecularevolution is approximately constant in all evolutionary lineages.( 中性学说认为,中性突变的突变速率等于分子进化的速率,且进化速率是恒定的。我们称其为分子钟。)