Evolution Sources Select Resources Encyclopedia Resource Type: Article In biology, evolution is change in the genetic material of a population of organisms through successive generations. Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population, a process that can result in the emergence of new species. Similarities among species suggest that all known species descended from a common ancestor (or ancestral gene pool) through this process of gradual divergence.
The World Without Us Resource Type: Book Published: 2007 A thought experiment to see what would happen to the planet if human beings simply disappeared.