Here's why:

* Phenotype: The observable characteristics of an organism, including its physical appearance, biochemical properties, and behavior.

* Species: A group of organisms that can interbreed and produce fertile offspring.

While members of the same species share a common gene pool, they are not identical. Differences in their genes (genotype) lead to variations in their phenotypes.

Examples:

* Humans: Even though we are all humans, we have different eye colors, hair colors, heights, and other physical characteristics.

* Dogs: All dogs belong to the same species, but different breeds exhibit vastly different physical appearances, temperaments, and abilities.

* Plants: Members of the same plant species can have different flower colors, leaf shapes, and growth habits.

In summary: The concept of phenotype applies to individuals within a species, highlighting the observable differences that arise due to genetic variations.