Correct option is A
The Red Queen Hypothesis, proposed by Leigh Van Valen, suggests that species must continuously evolve—not just for reproductive advantage but also to maintain their current fitness relative to others within an ever-changing environment. The metaphor comes from the Red Queen in "Through the Looking-Glass" who says, “It takes all the running you can do to stay in the same place.”
Now let’s evaluate the statements:
A. Within a lineage, organisms show a constant rate of extinction — Correct This fits Van Valen's observation that extinction rates are constant over time despite ongoing evolution.
B. Even in the absence of changing interactions, organisms are constantly evolving — Incorrect. This contradicts the Red Queen Hypothesis, which focuses on evolution in response to interactions, especially antagonistic ones like parasitism or predation.
C. Organisms with novel genotypes are at a selective disadvantage — Incorrect This actually goes against Red Queen dynamics, where novelty can be beneficial in overcoming parasites or predators.
D. Coevolution between two interacting species acts to maintain genetic variation through time — Correct. This is central to the Red Queen Hypothesis, especially in host-parasite arms races or predator-prey dynamics.
Hence, A and D align best with the Red Queen Hypothesis.
