* Variation is the foundation of natural selection: Natural selection can only act on traits that already exist within a population. If every individual were identical, there would be no differences for the environment to "select" for or against.
* Some variations are more advantageous: Certain traits might make an individual better suited to its environment, giving it a survival advantage. This could include traits related to finding food, avoiding predators, or surviving harsh conditions.
* Individuals with advantageous traits are more likely to reproduce: Those with traits that improve their survival chances are more likely to live long enough to reproduce and pass those traits onto their offspring.
* Over time, the population evolves: As generations pass, the frequency of advantageous traits increases in the population, leading to gradual changes in the species over time.
In essence, natural selection is a process of differential survival and reproduction based on pre-existing variations within a species.
