Adaptation and Natural Selection in Peppered Moths
Charles Darwin collected many facts to support his theory of evolution by natural selection. Although the evidence for evolution in the fossil record is very compelling, at the time of Darwin no one had observed evolution actually taking place. Darwin pictured the process of evolution as requiring vast amounts of time, far greater than a person's life span. Although Darwin was unaware of it, remarkable examples of evolution were going on around him in the countryside of his native England. One example of this evolution was happening to a species of moth known as the peppered moth, Biston betularia. The Industrial Revolution began in England in the middle of the eighteenth century. Since then, tons of factory soot has been deposited in the countryside around industrial areas in England. The soot has discolored and generally darkened the trees, rocks, and other natural features of the landscape. Before the Industrial Revolution, the wild type peppered moth was mostly light colored. A very rare form of the moth that was covered with gray spots was generally dark in appearance. In contrast, today the situation has reversed. Today in some areas over 90% of the peppered moths are dark in color. More than 70% of other moth species in England have also changed from a light to darker phenotype. Similar observations have been made in other industrial nations including the United States. How has this striking change come about? In this investigation, you will perform an experiment and use your data to offer and support an explanation.
In this investigation, you will simulate a predator/prey relationship.
You will determine whether color contrast has an effect on the ability
of a predator to rapidly locate prey. You will observe the impact on predation
in a population of peppered moths living just outside an industrial city.
Birds are the moth's natural predators.
III. Data Analysis and Questions
Each person in your group will answer at least one of the following
questions, but all of the questions must be answered. The group
will share their answers with the group's members. But each person must
turn in his or her own paper.