Use the following hypothetical situation to answer questions 10 and 11 imagine that there are two different populations of a single species of fish in a lake. one population of fish is pale-colored and one population is speckled.
now imagine that some of the pale-colored fish migrated into the speckled population and introduced new alleles into the population. will the population of dark-colored fish evolve?

imagine that, over time, part of the lake dries up and there are now two separate bodies of water. the speckled and pale-colored fish are evenly mixed in the two smaller lakes. will either population become more dominant?

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. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

What did hunter gathers do to alter the environment?

Long term exposure to waves can cause sunburns and skin cancer.