Final answer:
Racial groups among humans have developed due to migration patterns, cultural practices, environmental conditions, and genetic variability.
Step-by-step explanation:
The development of racial groups among humans has been influenced by a variety of factors. The phrases that accurately describe this development include migration patterns, which involve the movement of people and genetic mixing; cultural practices, which can lead to social structures that affect genetic diversity through mate selection; environmental conditions, which shape adaptations to different climates and circumstances; and genetic variability, which provides the raw material for natural selection and is affected by mutations, gene flow, and sexual reproduction.