Principle #1 Genetic Variation : Grasshoopers are found in feilds, gardens, and grassy areas. In the late summer the female grasshopper can lay up to 400 eggs. In the mid to late spring the baby grasshoppers will hatch.
Principle #2 Overproduction and selective pressures : The baby grasshoppers go through a month or two before becoming an adult. Changes in the season can make conditions favorable. The selective pressure is the season and weather change.
Principle #3 Differential Survival and Reproduction : Out of the 400 eggs laid the one that survive can reproduce offspring. The grasshoppers that live have to find grassy land. The reproduction only depends on the season and weather.
Prinicpal #4 Changes in the gene pool : The next generation will either decrease or increase depending on the season. The season will determine which eggs will survive and which will live.