In a city in Australia there is a population of moths that live in the grass, rarely taking flight except for short journeys. There are two phenotypes for wing color: green and beige. The largest predator of moths are birds and bats that prey upon the moths as they rest upon blades of grass. Green moths fare better in wet conditions when the grass takes on a lush green color and beige moths fare better in dry conditions when the grass turns a dry brown color.

(a) Identify which color moth was the most plentiful between 1969 and 1995.
(b) Explain why the lines of the graph never exceed 100.
(c) Predict during which years there was a drought.
(d) Explain how natural selection led to the rise of the beige moth in the late 1970s.

Transcribed Image Text:

Percentage of Moth Population 100 90 80 70 60 50 40 30 20 10 0 Percentage of Moths of Each Color 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 Green -- Beige