Principle #1 Genetic Variation The genetic variation within the population is turtles with tan shells and green shells.
Principle #2 Overproduction & The Struggle for Existence Many of the tan shell turtles have been produced more than the green shell turtles and only half that are born survive. Many green shell turtles are being eaten by the predators.
Principle #3 Differential Survival & Reproduction The tan shell turtles have a better and higher fitness and will survive and reproduce more than the green shell turtles
Principle 3$ Changes in Gene Pool The tan shell turtles will become more common in the population over time.