What are homogeneous and heterogeneous populations?
Homogenous populations are alike and heterogeneous populations are unalike.
Homogenous means alike.
Heterogenous means unalike or distinct from one another.
Thus, a homogenous population has little variation. You could refer to a specific trait, such as hair color or you could refer to genetic diversity. For example, a population of humans that has inhabited an island for thousands of years with little migration to or from the island is likely relatively homogenous or alike in their traits.
A heterogenous population is one where individuals are not similar to one another. For example, you could have a heterogenous population in terms of humans that have migrated from different regions of the world and currently live together. That population would likely be heterogenous in regards to height, hair texture, disease immunity, and other traits because of the varied background and genetics.
Let's say the image below represents two populations of parrots. The homogenous population has parrots of the same size and color. The heterogeneous population has parrots of different sizes and colors.