Question

The Red Queen effect refers to the fact that?

1) Parasites often kill their hosts, and therefore act as potent agents of selection on host populations.
2) Host immune systems evolve continuously and quickly in an arms race with parasite populations that are also evolving to evade their defenses.
3) Parasites evolve faster than their hosts.
4) Social insect colonies often have reproductive queens who actively suppress the reproductive capacity of worker females in the colony.
5) All of the above.
6) None of the above.

Answer 1

The Red Queen effect refers to how host immune systems must evolve continuously to match the evolution of parasites trying to evade their defenses; it is best supported by the example of an asexual snail population dying out due to a parasitic invasion.

Step-by-step explanation:

The Red Queen effect refers to scenario 2: Host immune systems evolve continuously and quickly in an arms race with parasite populations that are also evolving to evade their defenses. This concept is based on the idea that organisms must constantly adapt and evolve, not just to gain an advantage, but to maintain their current status in an environment where other organisms are also evolving.

The term originates from Leigh Van Valen's hypothesis, which uses the Red Queen's quote from Lewis Carroll's 'Through the Looking-Glass' to describe this evolutionary arms race. It emphasizes the necessity of ongoing variations and improvements for surviving in a competitive ecological landscape where entities must evolve at a similar pace to their antagonists, such as parasites and hosts. The best support for the Red Queen Hypothesis is found in example b: Individuals of a snail population that reproduce asexually die out after a parasite invades its territory, as it exemplifies the struggle of a species to survive when it cannot evolve quickly enough to fend off a parasitic threat.