Many mutations are harmful. Some may be harmless or even beneficial. An adaptive trait is any trait that helps an organism survive and reproduce under a given set of environmental conditions. B. Evolution 1. The frequencies of genes and the effects they cause can change over time.
Evolution is the change that characterizes populations through successive generations.
C. Natural Selection 1. Charles Darwin reasoned that the practice of artificial selection used by pigeon breeders could serve as a model for his theory of natural selection. Any population evolves when some forms of traits increase in frequency and others decrease or disappear over generations. Evolutionary processes help explain life's diversity. The Nature of Biological Inquiry A. Observations, Hypotheses, and Tests 1.