Following their respective breeding seasons, several species of hummingbirds occur at the same locations in North America and several hummingbird flowers bloom simultaneously in these habitats. These flowers seem to have converged to a common morphology and color. Birds are most visually sensitive to the color red. Hummingbird flowers are pollinated by hummingbirds. Which of the following features of these flowers would indicate they have coevolved with hummingbirds? (Check all that apply.)A) Long tubular flowersB) Flowers are colored violet and blueC) Blooming time of the flowers coincides with the arrival of the hummingbirdsD) Flowers produce a high volume of nectar and sugarE) Flowers are low to the ground

Question

What will be an ideal response?

Answer 1

A, C, D

Clarify Question
• What is the key concept addressed by the question?
        o The question requires an understanding of coevolution and what type of environmental conditions can contribute to coevolution in the flowers and the hummingbirds that visit them.
• What type of thinking is required?
        o This is an application question; you need to apply your knowledge of coevolution to determine which features represent evidence of coevolution between the hummingbirds and the flowers. This is a check-all-that-apply question; there is more than one correct answer.

Gather Content
• What do you already know about coevolution? What other information is related to the question? 
        o Coevolution occurs when 2 species evolve in lockstep with each other. Coevolution can lead to an "arms race" type of interaction when it occurs between competitors or predator/prey pairings, but it can also be mutually beneficial if the interaction species are in a mutualistic relationship to begin with.

Choose Answer
• Given what you now know, what information is most likely to produce the correct answer?
        o Hummingbird flowers have evolved to attract hummingbirds. They have long tubular flowers that are generally red in color. The flowers, which are generally on stalks, produce a high volume of sugar and nectar since hummingbirds have a high energy requirement.

Reflect on Process
• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o You needed to apply your knowledge of coevolution to the situation of the hummingbirds and the flowers they are feeding on. Were you able to identify the characteristics that were similar in the different species flowers and how those characteristics relate to attracting hummingbirds?