The variation of organisms within a species increases the likelihood that at least some members of the species will survive under changed environmental conditions.
Learning Goal 1b
A great diversity of species increases the chance that at least some living things will survive in the face of large changes in the environment.
Evolution of Life
For Grades: 9-12
Learning Goal 9
Evolution builds on what already exists, so the more variety there is, the more there can be in the future. But evolution does not necessitate long-term progress in some set direction. Evolutionary change appears to be like the growth of a bush: Some branches survive from the beginning with little or no change; many die out altogether; and others branch repeatedly, sometimes giving rise to more complex organisms.