When a dog has one brown puppy and one black and white puppy, what type of variation is this an example of?

The presence of one brown puppy and one black and white puppy in the same litter is an example of variation within a species. This type of variation occurs due to genetic differences among individuals of the same species. In dogs, various coat colors and patterns are a result of the diverse combinations of genes inherited from their parents. Such differences arise from the genetic variation that exists in the breeding population, not from differences between separate species or from adaptations over time. This scenario highlights how even within a single species, individuals can show distinct physical characteristics, underscoring the concept of genetic diversity within that species.