* Natural selection acts on populations, not individuals: Natural selection is the process by which organisms with traits better suited to their environment are more likely to survive and reproduce. It's a gradual process that happens over generations.
* Individuals don't evolve: While an individual organism might develop adaptations during its lifetime, these changes are not passed down genetically to offspring. Evolution, the process of change in a population over time, is driven by genetic changes that are inherited.
* Variations are key: Natural selection requires variation within a population. These variations arise from mutations in genes, which are passed down from parent to offspring. A single individual doesn't have enough genetic diversity to demonstrate natural selection.
An example:
Imagine a population of rabbits with varying fur colors. Some rabbits have brown fur, others have white fur, and some have a mixture of both. If the environment changes and snow covers the ground for long periods, rabbits with white fur will be better camouflaged and less likely to be preyed upon. Over time, the population of rabbits will shift towards having more white fur because those individuals are more likely to survive and reproduce.
In summary: Natural selection is a population-level phenomenon that acts on variations in traits over many generations. An individual organism cannot evolve through natural selection because it doesn't have the genetic diversity needed for the process to occur.
