Question

Given the strength of selection that bumblebees exert on alpine skypilots, why haven't flower corollas in the tundra population evolved to be even larger than they are now? Develop at least two hypotheses, and describe how you could you test your ideas.

Answer 1

One hypothesis is that there may be a trade-off between corolla size and other fitness traits. Another hypothesis is that bumblebees may not exert strong enough selection pressure. To test these hypotheses, field experiments and comparisons across populations could be conducted.

Step-by-step explanation:

One hypothesis for why flower corollas in the tundra population have not evolved to be larger than they are now is that there may be a trade-off between corolla size and other fitness traits.

For example, larger corollas may require more energy to produce and maintain, which could reduce the plant's overall fitness. Another hypothesis is that bumblebees may not exert strong enough selection pressure on corolla size to drive significant evolutionary changes.

To test these hypotheses, researchers could conduct field experiments manipulating the size of flower corollas and observe the fitness consequences. They could measure traits such as pollination success, seed production, and plant survival to determine if any trade-offs exist.

Additionally, researchers could compare corolla size and bumblebee visitation rates across different populations to assess the strength of selection pressure.