Which statement about natural selection is true? Natural selection tends to increase the risk of dying from external forces. Natural selection "weeds out" alleles that cause death in early life. Natural selection has produced increasing numbers of people who choose never to have children. Natural selection has produced a high degree of infant mortality in humans, compared to other species. Natural selection operates only on people of advanced age.

Read the following scenario to answer the following question. over the past 60 years, many amphibian species have experienced significant population declines, and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. when most populations of a wide-ranging amphibian species are lost and the few remaining populations are widely separated, we expect to see that a. the founder effect becomes increasingly important b. microevolution no longer occurs c. gene flow between populations is reduced d. artificial selection becomes a greater factor in microevolution

In this case, the statement that people who exercise for an hour may have lower cholesterol levels is .

What are the three types of counseling established by marine corps policy?