个体的发育取决于两个相互作用着的因素——遗传因素和环境因素。个体间的遗传成分或称基因组是在受精时建立起来的,尔后基因和环境(包括内环境和外环境)复杂的相互作用构成个体的发育。尽管基因一般保持不变,但环境的经历持续不断地变化着,甚至可能通过突变,或称基因的遗传性变异而改变基因组。有些遗传成分可能存在于所有 The development of an individual depends on two interacting factors - genetic and environmental. The genetic elements or genomes of individuals are established during fertilization and the subsequent complex development of genes and environment (including internal and external environments) constitutes the development of the individual. Although genes generally stay the same, the experience of the environment continues to change, perhaps even changing the genome through mutations, or genetic heritability. Some genetic elements may exist at all