Chapter 28, Problem 1Q

Summary Introduction

To review:

The dependency of expected floral colors of the two species of Mimulus on their respective pollinators.

Given:

In the given study, two species of the monkeyflower Mimulus cardinalis and M. lewisii were compared on the basis of their pollinators. Figure 1 given below shows the two species of monkeyflower (Mimulus).

Figure 1: The two species of monkeyflower (Mimulus).

Introduction:

Pollination plays an important role in the life cycle of a plant. It helps in fertilization of the male gametes (pollens) with the female gametes (ovules). Pollination is carried out with the help of different agents like insects, birds, and animals. Every organism visiting flower does not cause pollination.

Explanation of Solution

The two flowers being closely related need not to have same morphology. The morphology of flowers is decided by their genetic trait. Apart from the genes, the type of pollinators leads to the adaptation and speciation of the flower species.

M. cardinalis is pollinated by hummingbirds while M. lewisii pollinated by bees and other insects (as shown in Figure 2 below). They are also isolated from each other through geographical distribution, which has led to the difference in colors of petals.

Figure 2: Pollinators in M. cardinalis (above) and M. lewisii (below).

Conclusion

Hence, the pollinators play an important role in the morphology of flowers, which also lead to the difference in the colors of closely related species.