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.
여러분도 아시다시피 종들은 특정한 생태학적 틈새와 특정 환경에서 살았고, 그런 환경의 압력은 무작위한 돌연변이를 거쳐 어떤 변화가 보존될 것인지 결정하였습니다.