Final answer:
Biologists and anthropologists argue that there is no scientific basis for classifying humans into racial categories. Genetic markers for physical traits like skin color do not align with racial categories, and there is more genetic variation within races than between them. Race is a social construction, not a biological reality.
Step-by-step explanation:
Biological anthropology and genetics have shown that there is no valid scientific basis for classifying humans into racial categories. While there are genetic markers for physical characteristics like skin color and hair texture, these markers do not align with the convenient categories we use to categorize races. In fact, there is more genetic variation within racial categories than between them. The concept of race is a social construction and does not reflect biological reality.