Given a population that contains genetic variation,what is the correct sequence of the following events,under the influence of natural selection? 1)Well-adapted individuals leave more offspring than do poorly adapted individuals. 2)A change occurs in the environment. 3)Genetic frequencies within the population change. 4)Poorly adapted individuals have decreased survivorship.
The role that humans play in artificial selection is to
A)determine who lives and who dies. B)create the genetic variants, which nature then selects. C)choose which organisms breed, and which do not. D)train organisms to breed more successfully. E)perform artificial insemination.
Which of the following must exist in a population before natural selection can act upon that population?
A)genetic variation among individuals B)variation among individuals caused by environmental factors C)sexual reproduction D)Three of the responses are correct. E)Two of the responses are correct.