What's science and what does science come from

Which of the following typically characterizes a tropical rainforests

Which statement describes how favorable traits in a population relate to natural selection? they are the only traits that ever exist in the population. they build in the population over time. they are rarely passed on to offspring. they are found only in a few individuals within the population.

When a population split into two subgroups what is most likely to cause the subgroups to develop different traits?