Genes vary in natural populations. Gene Variation Is the Raw Material of Evolution. Selection acts on the genetic variation present in populations, favoring variants that increase the likelihood of survival and reproduction
Unit two Section A: Environmental Protection throughout the world about the text Ecology is the study of the relationships among plants, animals, people, and their environment, and the balance among these relationships
December 1998 Criteria ewage Works Design Contact Information Publication History To order printed copies of this manual, contact Originally published 1978(Pub. No. 78-5) Revised october 1985 Department of Ecology Publications distribution