Evolution 123

• The theory of natural selection is based on two main observations that Darwin made: 1. Traits are heritable 2. More offspring are produced than can survive
• Natural selection


  A process in which individuals that have certain traits tend to survive/reproduce at higher rates than other individuals because of those traits
• Phenotypic


  Characteristics can be passed from parent to offspring
• Artificial selection is the selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits
• Populations evolve, not individuals
• Some phenotypes will increase fitness (ability to survive and reproduce), measured by reproductive success
• Adaptations


  Inherited characteristics of organisms that enhance their survival and reproduction
• Characteristics can be passed from parent to offspring
• This leads to competition for limited resources, which results in differential survival
• Both natural and artificial selection can lead to evolutionary change in organisms
• Natural selection acts on traits that lead to survival and reproduction
• Survival of the fittest" refers to the organisms in a population that are the strongest, healthiest, and fastest
• Evolution is a change in the genetic makeup of a population over time; descent with modification
• Evolution is the change in the genetic makeup of a population over time; descent with modification