29. B) A population changes in response to a change in the environment.
Evolution is the process by which new species of organisms develop from earlier forms. Most often, in response to a change in a species environment. It's the frequent change of the alleles in a population.
30. A) Describes the relationship between an organism and its environment
Darwin made this theory of evolution by natural selection as an explanation for adaptation. Darwin defined natural selection as the
"principle by which each slight variation, if useful, is preserved."