Physical anthropology, also known as biological anthropology, is the anthropological counterpart to the various biological sciences that deal with the study of human beings. Physical anthropology studies living human beings and also, non-human primates, along with extinct relatives and ancestors of humans, in different environmental stresses and conditions that exist, and existed, in the World. The two main aspects of study of this branch of anthropology are; human evolution and human variation.
Human origin and evolution are one of the chief concerns of physical anthropologists. Through analysis of fossils and observation of living primates, they try to trace man's ancestry and understand his relationship with other living beings. Physical anthropology also tries to provide a comparative perspective on human uniqueness by placing Homo sapiens in the context of other living primates. The other major aim of physical anthropology is to understand human diversity and variation. being members of the same species, there is significant biological variation among the Homo sapiens. Not only visible traits but also biochemical factors such as blood type and susceptibility to diseases. Human beings have covered nearly all kinds of geographical zones of the World, hence the study of human adaptation is also an important part of physical anthropology.
The initial concern of physical anthropology however was to describe the variation of a few features in human beings, mainly referring to measurements, computing indices and other statistics. Today, it not only describes the variation of hundreds of features but also encompasses the entire history and nature of biological change among human beings. This represents an enormous expansion in its scope. Because of the wide scope, physical anthropology can be divided into subbranches, each focusing on a different dimension of what it means to be human - from a biological perspective. Refer : Branches of - Physical/Biological Anthropology