Marsupial mole rats evolved in New Zealand in the 1700s and had few natural predators so they overpopulated the area. Scientist developed a virus to bring their numbers down, which was successful for awhile. After several generations though, their numbers began to increase. Why? *
A. Marsupial mole rats mated with other mole rats and created a new species.
B. Marsupial mole rats learned to survive regardless of being sick.
C. Some marsupial mole rats had a natural immunity to the virus.
d. Marsupial mole rats changed their reproductive cycle and were able to reproduce more.

C. Some marsupial mole rats had a natural immunity to the virus.

Explanation:

According to Darwin's evolutionary theory, over time some of marsupial moles may have acquired natural immunity which evolves as an adaptive trait in the population. Since these organisms have more chance to survive and reproduce (survival of the fittest), they will likely transmit the natural immunity to the next generation .

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.