The Red Queen Hypothesis

Question 1

A new strain of myxomatosis virus spreads through a rabbit population. Over several rabbit generations the virus mutates so it can avoid the rabbits' current immune response. According to the Red Queen hypothesis, which change is most likely to occur in the rabbits to keep them as fit as before?

Accepted Answer

Rabbits evolve a stronger immune protein that can recognize the new virus strain.

Answer

Rabbits grow longer ears to hear predators better.

Answer

Rabbits start eating more carrots to gain extra energy.

Answer

Rabbits become more social and live in larger colonies.

Question 2

Scientists observing the night‑blooming orchid Lunaflora and the hawk moth Silversky find that the orchid’s nectar tube is about 5 cm deep, which is the same length as the moth’s proboscis. Which statement best explains why this matching length shows co‑evolution?

Accepted Answer

Moths with slightly longer proboscises could reach the orchid’s nectar and survived better, and orchids with slightly deeper tubes got more visits from those moths, so both traits became longer together over many generations.

Answer

The moth’s long proboscis lets it drink from many different flowers, and the orchid’s deep tube evolved only to protect its nectar; the similar lengths are just a coincidence.

Answer

The orchid grew a deep tube to keep out insects that cannot reach the nectar, while the moth happened to have a proboscis of the same length; no mutual influence happened.

Answer

A longer proboscis would damage the orchid’s delicate petals, so natural selection favored moths with shorter proboscises; the orchid’s deep tube is unrelated.

Question 3

A cheetah can sprint up to about 110 km/h, while a gazelle can run about 80 km/h. Over many generations the cheetah population has become roughly 5 % faster, and the gazelle population has become about 4 % faster. Which explanation best describes why both species continued to evolve these speed changes?

Accepted Answer

Because the cheetah and gazelle are in an evolutionary arms race: each time the cheetahs get faster, gazelles that can run a little faster survive better, and each time the gazelles get faster, cheetahs that are slightly faster catch more prey, so both must keep evolving to stay fit.

Answer

Only the cheetahs need to evolve faster because they are predators; the gazelles do not need to change since they can already escape the cheetahs.

Answer

The speed increases are caused by a warming climate that makes the grass taller, not by any interaction between the cheetahs and gazelles.

Answer

As cheetahs become faster they will eventually eliminate the gazelles, so gazelles no longer need to evolve any further.

Try three questions

A new strain of myxomatosis virus spreads through a rabbit population. Over several rabbit generations the virus mutates so it can avoid the rabbits' current immune response. According to the Red Queen hypothesis, which change is most likely to occur in the rabbits to keep them as fit as before?

Scientists observing the night‑blooming orchid Lunaflora and the hawk moth Silversky find that the orchid’s nectar tube is about 5 cm deep, which is the same length as the moth’s proboscis. Which statement best explains why this matching length shows co‑evolution?

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