Key Terms

• Natural Selection

  A process where the phenotypes best adapted to a niche means the organism is more likely to survive and pass on its genes.
• Genetic Variation

  Diversity of genetic traits within a species.
• Phenotype

  Observable characteristics of an organism.
• Omnivore

  An organism that eats both plants and animals.
• Carnivore

  An organism that eats only other animals.
• Herbivore

  An organism that eats only plant material.
• Selection Pressures

  Environmental factors influencing organism survival.
• Reproductive Isolation

  The inability of groups to interbreed and produce fertile offspring.
• Niche

  A specific role or position that an organism occupies within its envrionment.
• Speciation

  Formation of new and distinct species in the course of evolution.
• Mutation


  A random, permanent change in the base sequence of an organism.
• Gene Pool


  The total collection of different gene in a population.
• Genetic Drift

  Random changes in the frequency of alleles in a population.
• Allele

  A variant form of a gene.
• Phenotype

  The observable characteristics of an organism.
• Inbreeding

  Breeding between two closely related individuals.