Archaeology is the study of past human cultures. Like cultural anthropologists, archaeologists are interested in all aspects of culture. Unlike cultural anthropologists, however, they do not always have the benefit of living peoples who can teach them about their cultures. For this reason, archaeologists must rely on material culture, since artifacts and other forms of material vestiges are often all that remains of past cultures. Through systematic methods of excavation and examination of these objects from the past, archaeologists are able to determine how a society utilized resources in the physical environment for food, tools, clothing, shelter and transportation. Often, archaeologists can also trace the paths of trade and commerce, the type of social organization, the religious beliefs and rituals, as well as the political structure of the society in question. Whereas cultural and linguistic anthropology offer the discipline comparative breadth among contemporary and historic peoples, archaeology provides a comparative view by documenting the grand scale of human existence from the emergence of stone tools through the origins of agriculture to the rise and fall of cities and states.
Biological Anthropology, also known as physical anthropology, examines the biological traits of humans past and present, and how these traits interact with cultural factors to produce human variation through time and across space. Biological anthropologists also study the evolutionary origins of the human species from non-human primates that began many millions of years ago. Traditionally, biological anthropologists relied mainly on fossilized skeletal remains for their studies. Recently, however, advances in the field of genetics have enabled them to examine ancient DNA for clues to our origins. A related field focuses on primatology, the study of the behavior and biological traits of modem apes and monkeys in order to gain greater understanding of our distant ancestors. In the contemporary world, forensic anthropology, which deals with the application of biological anthropology methods to legal issues (e.g identification of crime victims), is a very dynamic branch of biological anthropology. In common with the other three subfields of anthropology, biological anthropology uses the comparative method to test the boundaries between the culturally constructed and the biologically determined.
Cultural Anthropology (or sociocultural anthropology) takes human society and culture as its subject matter. Cultural anthropologists study such cognitive phenomena as beliefs, systems of knowledge, and symbols, as well as such products of human labor as technologies and the arts. They are also interested in human behavior as expressed in social structures and social relations, as well as economic and political systems. Cultural anthropology shares many things in common with related fields, such as sociology and psychology. What makes it unique, however, is that it examines not only larger social dynamics (similar to sociology's focus on class, gender, ethnicity, etc.) and the ways that people think and feel (similar to psychology's emphasis on human thought), but it also probes deeply into the cross-cultural variation of social behavior and the meanings of fundamental categories such as "man," "woman," "thought," or "mind." This comparative perspective on culture brings into focus the extent of both human diversity and common humanity.
Linguistic Anthropology is the study of human language and communication. Linguistic anthropologists study the origins of language in general and the histories of particular languages and language families. They are also interested in the dynamics of contemporary linguistic change, how language is learned, the role of language in systems of thought, and the relationship between language and other aspects of culture (e.g. oral traditions, politics, mass media, and expressive arts such as music and theater). An emerging field within linguistic anthropology deals with the role of language in power hierarchies along lines of class, gender, race and nationality. In common with cultural anthropology, linguistic anthropology incorporates a crosscultural comparative perspective to shed light on the elusive line between human nature and human culture.