1. Variation: Individuals within a population exhibit natural variations in their traits. These variations can be inherited, meaning they can be passed down from parents to offspring.
2. Natural Selection: In a given environment, some variations are more advantageous than others. Individuals with these advantageous traits are more likely to survive, reproduce, and pass on their traits to their offspring. This process gradually leads to the accumulation of favorable traits in a population, resulting in evolution over time.
It's important to note that Darwin did not fully understand the mechanism of inheritance, which was later explained by Gregor Mendel's work on genetics.
