Question

cameron magee - natural selectionintroduction: the 19th century was the time of the industrial revolution in england. most of the new industries used coal for energy, and the air was polluted with black soot. in forests near factories, the soot coated trees and killed lichens. as a result, tree trunks became darker.question: how did air pollution affect moth populations?1. predict: over time, what will happen to the populations of light and dark moths on dark trees?2. experiment: click play and hunt peppered moths on dark tree trunks for five years. in each year, try to capture as many moths as you can.when you are done, select the table tab and record the percentages of each moth type.3. analyze: what do your results show?4. apply: which type of moth do you think was more common during the 19th century? why?(activity b continued on next page)

Explanation:

1. Predict: Dark tree trunks camouflage dark moths, making light moths easier prey. Over time, natural selection will favor dark moths, increasing their population while light moths decrease.
2. Experiment Table (Simulated Expected Results): These values reflect natural selection trends, with dark moths becoming more common as light moths are predated more easily.
3. Analyze: The results show that dark moth populations rise over time, while light moth populations fall, demonstrating that camouflage from tree trunk color reduces predation.
4. Apply: Dark moths were more common in the 19th century. Industrial pollution darkened tree trunks, so dark moths were better camouflaged and less likely to be eaten by predators, allowing their population to thrive.

Answer:

1. Predict: The population of dark moths will increase, and the population of light moths will decrease.
2. Experiment (Expected Results Table):

Year	Dark moths	Light moths
1	60%	40%
2	70%	30%
3	78%	22%
4	85%	15%
5	90%	10%

1. Analyze: Dark moth populations increase annually, while light moth populations decrease, showing that dark moths are better adapted to dark tree trunks.
2. Apply: Dark moths were more common during the 19th century. Dark tree trunks from industrial soot camouflaged dark moths, so they were less likely to be hunted by predators compared to visible light moths.