There are about 1,000 susceptible people living in this 1 km2 village. People who catch the disease stay sick for about 3 days, and you estimate the chance an infected individual will pass the disease to a susceptible they meet is 0.0002. What is R0 for this disease?

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.