Principle 2: Overproduction and the struggle to survive
Principle 3: Differential Survival and Reproduction (Survival of the Fittest)
A species of a tan lizard have migrated to a swampy marsh with all the organisms of the species being 100% tan.
Principle 4: Change in the Gene Pool
Some of the species have mainted to adapt to the dark grass of the marsh due to predators easily spotting the tan lizard.
Lizards lay up 8 eggs at once. only those best fit for their environment will be able to evade predators and live to reproduce.
The Lizard who've inherited the dark green traits will be the fittest and'll be the ones who reproduce and pass traits to their offspring. occasionally lizards will be tan because of the existing gene from previous generation.
The lizards have been 100% tan but were rapidly being hunted by their predators in their new marsh environment so over generation they changed color.