Milkweed is the common name for many plants in the genus Asclepias. It is an herbaceous perennial, recognizable by its broad opposite leaves, colorful flower clusters, or seed pods filled with silk that carries its wind-dispersed seeds.
Monarch butterflies only lay eggs on milkweed, and monarch caterpillars only feed exclusively on milkweed leaves. making the milkweed the only host plant for this butterfly species. There is a symbiotic relationship between the monarchs and the milkweed. The butterflies benefit by eating the nectar from the flowers, and the milkweed benefits by getting help with pollination. There is also a very specialized relationship between the monarch caterpillars and the milkweed. There is a milky latex produced by the plant, which contains compounds called cardiac glycosides that are poisonous to most other animals. The monarch butterfly has developed resistance to this toxin, giving caterpillars a strong chemical defense against predators. In response, milkweed is trending toward faster regrowth following monarch caterpillar activity rather than increased toxicity. This is an example of coevolution, the process of living things influencing one another over thousands or millions of years
5. What argument can be made, which could be supported by the evidence collected in the graph below, between the changes to the biological components (i.e. habitat, food source, egg laying location) of an ecosystem and the population of the Monarch butterfly?
•If the milkweed population continues to decrease then the monarch population will begin to recover and
•If the monarch population begins to recover and increase then the milkweed population will eventually go extinct.
•If the milkweed population begins to recover and increase then the monarch population will also begin to recover and increase.
• The milkweed population has no affect on the monarch population.