Principle 2: Overproduction and the Struggle to Survive
Principle 3: Differential Survival and Reproduction(Survival of the Fittest)
There is a population of Chuckwallas in the desert. The Chuckwallas that are dotted have eyes that are on top of their head for peripheral vision and the plain brown ones have eyes in the front, so they have no peripheral vision.
Principle 4: Change in the Gene Pool
The plain brown Chuckwallas struggle to survive because they can't see any predators above them, such as birds. The dotted Chuckwallas are populating more because they are able to run when they see birds.
Organism: Chuckwalla Environment: Desert Trait selected for: Eyes on the back of the head for peripheral vision. Adaptation Type: Physical- Structural
The dotted Chuckwallas are able to survive because of their peripheral vision. Meanwhile, the plain Chuckwallas are dying out fast.
The dotted Chuckwallas got to reproduce and survive. This means that the gene pool has changed from plain brown Chuckwallas and dotted Chuckwallas to just dotted Chuckwallas.