In this forest, there were multiple variations among our population, separated by each's phenotype, such as the color of fur in brown, white, and grey.
Oh yes, never thought I could get a taste on ratatouilles.
Soon, overpopulation occurred and surpassed our carrying capacity, which meant we had to compete for limited resources. Along with arrival of the new predator, the process of natural selection began.
Yes, I do have spare space in my stomach.
Spare me Please!
Hide and Squeak Too Easy.
Since our heritable adaptation of brown fur allowed us to camouflage with the dirt, we were better suited in the environment. This is known as the Survival of Fittest.
Since more of the brown rats survived, we had a higher chance of producing fertile offspring than others. Our adaptation was more favored than those who were flavored to the birds.
We were becoming more common than white and grey rats, because our color is a inheritable trait, the environment favored our brown fur.
Eventually, the population of brown rats gradually increased and accumulated favorable modifications or adaptations to become more suitable for the environment compared to those who lacked of those traits. We then passed down our traits to our fertile offspring, showing the process of Natural Selection. Cheese to our ancestors and parents.