Question

The interactions between the American chestnut and the parasitic fungus Cryphonectria parasitica best exemplify the principle that

a. vaccination can reduce the incidence of disease.
b. selection can favor a diversity of host and parasite genotypes.
c. parasites can influence host population cycles.
d. parasites can drive host populations to extinction.

Answer 1

The destruction of the American chestnut by the fungus Cryphonectria parasitica illustrates that parasites can indeed drive host populations to extinction, supporting the Red Queen Hypothesis.

Step-by-step explanation:

The interactions between the American chestnut and the parasitic fungus Cryphonectria parasitica best exemplify the principle that parasites can drive host populations to extinction. The introduction of the chestnut blight caused by Cryphonectria parasitica to North America led to the near-elimination of the American chestnut, which profoundly impacted the forest ecosystem structure and the loss of host-specific moth species. This situation illustrates a broader ecological and evolutionary implication where pathogens can lead to host extinction, supporting the idea that co-evolution between species is a continuous arms race, as proposed by the Red Queen Hypothesis.