natural seed selection自然选种
natural l selection自然选择;物竞天择
eco-natural line selection and design自然生态化选线及设计
theory of natural selection自然选择学说;自然选择说;天择说
Natural Selection and Evolution自然选择与进化;自然选择与演化
secondary natural selection次生自然选择
The Natural Selection Theory自然选择论
Natural Selection Annex物竞天择附属区
directional natural selection定向自然选择
N-UNCOUNT（不可数名词） Natural selection is a process by which species of animals and plants that are best adapted to their environment survive and reproduce, while those that are less well adapted die out. (生物的)自然选择; 物竞天择
Natural selection ensures only the fittest survive to pass their genes on to the next generation.
物竞天择确保只有最适应环境的物种才得以生存下来，把基因传递给下一代。