# Biological Evolution and Early Human Evidence

## What Is Biological Anthropology?


### Learning Outcomes:

By the end of this section, you will be able to:
1. Identify the five subfields of biological anthropology.
2. Explain how each of the subfields contributes to our understanding of human origins and evolution.
3. Understand the historical context of the field of biological anthropology.

### Looking to the Deep Past

Biological anthropology, also referred to as physical anthropology or evolutionary anthropology, is one of the four major subfields of anthropology. While the other subfields focus on current and relatively recent human cultures, biological anthropology looks to the deeper past, asking questions about what it means to be human by exploring where humans came from as a species. Biological anthropology comprises numerous areas of study: human biological variation, paleoanthropology (human and primate evolution), primatology (the study of nonhuman primates), bioarchaeology (the study of bones found at archaeological sites), and genetic anthropology (the application of molecular science to archaeological, historical, and linguistic evidence to reveal the history of ancient human origins and migration). Each of these areas of study contributes something to anthropologists’ understanding of current human physical characteristics and behaviors.

### Exploring What It Means to Be Human

Studies of human biological variation evaluate the physical similarities and differences between human populations across both time and space. Differences in morphology include features such as height, jawline, eye sockets, and ear and nose shape and size. Biochemical differences account for variations in the sense of smell, mutations in the CCR5 gene that offer resistance to HIV, and variations in skin pigmentation in response to levels of exposure to ultraviolet rays from the sun.
The study of human biological variation is closely linked to the original conception of biological anthropology, which was formalized in 1930 with the establishment of the American Association of Physical Anthropologists, recently renamed the American Association of Biological Anthropologists. The change in name is an effort to move away from the term physical anthropology, which has come to be associated with views promoting scientific racism that no longer represent or align with views held by anthropologists today. In 1951, American anthropologist Sherwood Washburn introduced a “new physical anthropology,” changing the focus from racial typology and classification to the study of human evolution and the evolutionary process. This new focus expanded anthropology as a field to include paleoanthropology and primatology
Paleoanthropology looks at the fossil evidence of humanity’s ancestors along with ancient material culture such as tools and other human artifacts. The physical morphology (shape and size) of skulls and other postcranial material (skeletal remains other than the skull) allow paleoanthropologists to form hypotheses about important milestones in human evolution over time.
Primatology examines the behavioral and physical attributes of both living and fossil primates as well as their relationships with their environments. Humans are primates who share a common ancestry with nonhuman primates. By studying nonhuman primates, anthropologists can gain a better understanding of what it means to be a primate and what it means to be human.
Genetic anthropology is used within several areas of biological anthropology. In this specialized area, DNA testing is combined with archaeological, historical, and linguistic evidence to reveal the history of ancient human migration or to track human disease.
Forensic anthropology is a subfield of biological anthropology that applies scientific methods to the analysis of human remains for the purposes of identifying a victim and determining the possible cause of death. A major difference between forensic anthropology and other types of biological anthropology is that forensic anthropology is usually focused on crime scenes involving the death of an individual, whereas other types primarily focus on understanding patterns and features that may appear in a group or an entire population. Beginning in World War II, forensic anthropologists have been instrumental in helping identify victims of war and disasters. They have played critical roles in identifying victims of the Thailand tsunami in 2004 and the destruction of the World Trade Center on September 11, 2001. Today, most forensic anthropologists work in a medical examiner’s office, assisting with autopsies and examinations of skeletal remains.
Bioarchaeology studies human remains in archaeological settings with a focus on what skeletal material can reveal about the culture, diet, and presence of disease in a population. Bioarchaeologists are also interested in the socioecological system of a population, which helps anthropologists better understand the roles of environmental and ecological pressures and influences in shaping cultural identity, social inequity, sustainability, and access to and use of resources. Based on the biological remains found at archaeological sites, bioarchaeologists explore questions pertaining to social and funerary behavior, diet and nutrition, health, and disease. Bioarchaeology offers a window into the connections among biology, society, and culture. An example of what a bioarchaeologist might study is skeletal evidence of infant cranial boarding, which was practiced by many cultures, including the ancient Maya, the Inca, and some Native North American groups. The process involved binding a child’s head to a flat board in order to artificially deform the skull, possibly to meet an aesthetic ideal or to signify social status. Bioarcheologists have found that variations in how the board was attached to the skull provide important information about an individual’s social identity.