Final answer:
The classification of human beings is primarily covered by the field of Biological Anthropology. It examines human origins, genetics, and evolution using the principles of natural selection and evolutionary theory.
Step-by-step explanation:
The major branch of science that deals with the classification of human beings is Anthropology, specifically Biological Anthropology. This field focuses on the origins, evolution, and diversity of the human species by studying the earliest processes in the biological and sociocultural development of humans.
Biological anthropologists may study the human genome or analyze fossils to understand the evolutionary path of Homo sapiens. They often use evolutionary theory and principles of natural selection, as proposed by Charles Darwin, to comprehend how humans have evolved and adapted over time.
Additionally, the classification of humans within the animal kingdom, as chordates and mammals of the primate order, highlights our fundamental biological characteristics, including having a backbone, hair, and milk glands.