principle #1. genetic variation The lizard population has light green scale pigment while others have dark green scale pigments
Principle #2. Overpopulation& selective pressure. Though the lizards do not suffer from overpopulation, the light green pigmented lizards are being eaten by predators because they can not bled with their environment due to its more vibrant color, While the dark green pigmented lizards are surviving because they are not as easily spotted against the similar colored environment. The disability of their vibrant color for the light green lizards is a selective pressure that they are experiencing because it is altering their fitness.
principle #3. Differential survival & Reproduction. Since the dark green lizards are able to survive due to them not being eaten as much or at all, allows them to increase their fitness, mate, and reproduce. This will show the effect of the increase of dark colored lizards, and the decrease in light colored lizards.
Principle #4. Changes in the gene pool Moving forward, the generations made in the future or even currently, will inherit the dark color of their previous family member like mothers and fathers. Since this trait will continue to be passed down there will be more dark colored lizards and therefore more surviving members of the species. the darker colored lizards will continue to increase while the lighter ones will continue t decrease, unless they decide to find a more a habitat to match their light colors.