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Biology Ch. 15

Evolution A heritable change in the characteristics within a population from one generation to the next; the development of new types of organisms from preexisting types of organisms over time
Strata Layers of rock (singular, stratum)
Natural Selection The process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do; a theory to explain the mechanism of evolution
Adaptation The process of becoming adapted to an environment; an anatomical, physiological, or behavioral change that improves a population's ability to survive
Fitness A measurement of the ability of a species to respond to the pressures of natural selection; the ability of individuals to survive to propagate their genes
Fossil The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock
Superposition A principle that states that younger rocks lie above older rocks if the layers have not been disturbed
Relative Age The age of an object in relation to the ages of other objects
Absolute Age The numeric age of an object or event, often stated in years before the present, as established by an absolute-dating process, such as radiometric dating
Biogeography The study of the geographical distribution of living organisms and fossils on Earth
Homologous Structure Anatomical structures that share a common ancestry
Analogous Structure An anatomical structure in one species that is similar in function and appearance, but not in evolutionary origin, to another anatomical structure in another species
Vestigial Structure A structure in an organism that is reduced in size and function and that may have been complete and functional in the organism's ancestors
Phylogeny The evolutionary history of a species or taxonomic group
Convergent Evolution The process by which unrelated species become more similar as they adapt to the same kind of environment
Divergent Evolution The process by which two or more related but reproductively isolated populations become more and more dissimilar
Adaptive Radiation An evolutionary pattern in which many species evolve from a single ancestral species
Artificial Selection The selective breeding of organisms (by humans) for specific desirable characteristics
Coevolution The evolution of two or more species that is due to mutual influence, often in a way that makes the relationship more mutually beneficial
Created by: HuffmanV20