Chapter Eleven

Evolution

The change in the genetic makeup of a population with time is termed evolution. Evolution is explained by the constant propagation of new variations in the genes of a species, some of which impart an adaptive advantage. All living things (past and present) are descendents from a single common ancestor. Each of these organisms arose as a direct result of some genetic alteration in the species that lived before them, and this process is called evolution. Most evolutionary changes occur slowly over a long period of time.