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17 Cards in this Set

  • Front
  • Back
Any genetically controlled structural, physiological, or behavioral characteristic that helps an organism survive and reproduce under a given set of environmental conditions. It usually results from a beneficial mutation
The small genetic changes a population undergoes
natural selection
Process by which a particular beneficial gene (or set of genes) is reproduced in succeeding generations more than other genes. The result of natural selection is a population that contains a greater proportion of organisms better adapted to certain environmental conditions
reproductive isolation
Long-term geographic separation of members of a particular sexually reproducing species
Complete disappearance of a species from the earth. This happens when a species cannot adapt and successfully reproduce under new environmental conditions or when it evolves into one or more new species
ecological niche
Total way of life or role of a species in an ecosystem. It includes all physical, chemical, and biological conditions a species needs to live and reproduce in an ecosystem
Species with a broad ecological niche. They can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions. Examples are flies, cockroaches, mice, rats, and human beings
Long-term, large-scale evolutionary changes among groups of species
gene flow
Movement of genes between populations, which can lead to changes in the genetic composition of local populations
A random change in DNA molecules making up genes that can yield changes in anatomy, physiology, or behavior in offspring
theory of evolution
Widely accepted scientific idea that all life forms developed from earlier life forms. Although this theory conflicts with the creation stories of many religions, it is the way biologists explain how life has changed over the past 3.6-3.8 billion years and why it is so diverse today
fundamental niche
The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species
Species with a narrow ecological niche. They may be able to (1) live in only one type of habitat, (2) tolerate only a narrow range of climatic and other environmental conditions, or (3) use only one or a few types of food
adaptation radiation
Period of time (usually millions of years) during which numerous new species evolve to fill vacant and new ecological niches in changed environments, usually after a mass extinction
Formation of two species from one species as a result of divergent natural selection in response to changes in environmental conditions; usually takes thousands of years
Evolution in which two or more species interact and exert selective pressures on each other that can lead each species to undergo various adaptations
genetic drift
Change in the genetic composition of a population by chance. It is especially important for small populations