Imagine that you are writing a report on the people who most influenced a president during the administration. a president's personal thoughts have a source. which advisor would be the best source?
a. the national security advisor
b. the secretary of state
c. the attorney general
d. the chief of staff
e. the secretary of treasury

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.