So, as you all know, species lived in particular ecological niches and particular environments, and the pressures of those environments selected which changes, through random mutation in species, were going to be preserved.
那是，就一如你们所知的， 生物生活在特殊的生物环境 和特殊的生态环境下， 这些环境的生存压力 挑选出那些改变了的， 通过随机变异的生物体， 来进一步生存。