Biological anthropology uses a scientific and evolutionary approach to answer many of the same questions that all anthropologists are concerned with: What does it mean to be human? Where do we come from? Who are we today? Biological anthropologists are concerned with exploring how humans vary biologically, how humans adapt to their changing environments, and how humans have evolved over time and continue to evolve today. Some biological anthropologists also study what humans and nonhuman primates have in common and how we differ.
You may have heard biological anthropology referred to by another name—physical anthropology. Physical anthropology is a discipline that dates to as far back as the eighteenth century, when it focused mostly on physical variation among humans. Some early physical anthropologists were also physicians or anatomists interested in comparing and contrasting the human form. These researchers dedicated themselves to measuring bodies and skulls (anthropometry and craniometry) in great detail (Figure 1.10). Many also acted under the misguided racist belief that human biological races existed and that it was possible to differentiate between, or even rank, such races by measuring differences in human anatomy. Anthropologists today agree that there are no biological human races and that all humans alive today are members of the same species, Homo sapiens, and subspecies, Homosapiens sapiens. We recognize that the differences we can see between peoples’ bodies are due to a wide variety of factors, including environment, diet, activities, and genetic makeup.
The subdiscipline has changed a great deal since these early years. Biological anthropologists no longer identify human differences in order to assign people to groups, like races. The focus is instead on understanding how and why human and primate variation developed through evolutionary processes. The name for the subdiscipline has transitioned in recent years (from physical anthropology to biological anthropology) to reflect these changes. Many believe the term biological anthropology better reflects the subdiscipline’s focus today, which includes genetic and molecular research.
The Scope of Biological Anthropology
Just as anthropology as a discipline is wide ranging and holistic, so too is the subdiscipline of biological anthropology. There are at least six subfields within biological anthropology (Figure 1.11): primatology, paleoanthropology, molecular anthropology, bioarchaeology, forensic anthropology, and human biology. Each subfield focuses on a different dimension of what it means to be human from a biological perspective. Through their varied research in these subfields, biological anthropologists try to answer the following key questions:
- What is our place in nature? How are we related to other organisms? What makes us unique?
- What are our origins? What influenced our evolution?
- How and when did we move/migrate across the globe?
- How are humans around the world today different from and similar to each other? What influences these patterns of variation? What are the patterns of our recent evolution and how do we continue to evolve?
The terms subfield and subdiscipline are very similar and are often used interchangeably. In this book we use subdiscipline to refer to the four major areas of focus that make up the discipline of anthropology: biological anthropology, cultural anthropology, archaeological anthropology, and linguistic anthropology. When we use the term subfield we are referring to the different specializations within biological anthropology.
Primatologists study the anatomy, behavior, ecology, and genetics of living and extinct nonhuman primates, including apes, monkeys, tarsiers, lemurs, and lorises. Primatology research gives us insights into how evolution has shaped our species, since nonhuman primates are our closest living biological relatives. Through such studies, we have learned that all primates share a suite of traits. Primates, for instance, have nails instead of claws, possess hands that can grasp and manipulate objects (Figure 1.12), invest great amounts of time and energy in raising a small number of offspring, and employ complex social behaviors. Behavioral studies, such as those by Jane Goodall of wild chimpanzees and others, reveal that great apes are like humans in that they have families and form strong maternal-infant relationships. Gorillas mourn the deaths of their group members, and they exhibit behaviors similar to humans such as playing and tickling. Importantly, the work of Goodall, Karen B. Strier (see Appendix B), and others focus on primate conservation: They have brought attention to the fact that 60% of primates are currently threatened with extinction (Estrada et al. 2017).
Paleoanthropologists study human ancestors from the distant past to learn how, why, and where they evolved. Because these ancestors lived before there were written records, paleoanthropologists have to rely on various types of physical evidence to come to their conclusions. This evidence includes fossilized remains (particularly fossilized bones; Figure 1.13), DNA, artifacts such as stone tools, and the contexts in which these items are found. In recent years, paleoanthropologists have made some monumental discoveries about hominin evolution.
These findings helped us learn that human evolution did not occur in a simple, straight line but, rather, branched out in many directions. Most branches were evolutionary “dead ends.” Humans are now the only living hominins left on planet Earth. Paleoanthropologists frequently work together with other scientists such as archaeologists, geologists, and paleontologists to interpret and understand the evidence they find. Paleoanthropology is a dynamic subfield of biological anthropology that contributes to our understanding of human origins and evolution.
Molecular anthropologists use molecular techniques (primarily genetics) to compare ancient and modern populations as well as to study living populations of humans or nonhuman primates. By examining DNA sequences, molecular anthropologists can estimate how closely related two populations are, as well as identify population events, like a population decline, that explain the observed genetic patterns. This information helps scientists trace patterns of migration and identify how people have adapted to different environments over time.
Several molecular anthropologists have recently attracted international recognition for their groundbreaking work. For instance, in 2022, Svante Pääbo won the Nobel Prize in physiology (medicine) for his work extracting the DNA from 40,000-year-old Neanderthal bones and producing the first complete genome of Homo neanderthalensis. This was a challenging task because ancient DNA does not preserve well and older extraction techniques tended to become contaminated by the researcher’s and other environmental DNA. Pääbo and his team designed specialized clean rooms for handling ancient DNA and made advances in DNA sequencing. Their research helped scientists identify genetic differences between modern humans and Neanderthals and analyze how those differences influence how diseases, such as COVID-19, affect our bodies. Molecular anthropology is a quickly changing field as new techniques and discoveries shape our understanding of ourselves, our ancestors, and our nonhuman primate relatives.
Bioarchaeologists study human skeletal remains along with the surrounding soils and other materials. They use the research methods of skeletal biology, mortuary studies, osteology, and archaeology to answer questions about the lifeways of past populations. Through studying the bones and burials of past peoples, bioarchaeologists search for answers to how people lived and died, including their health, nutrition, diseases, and/or injuries. Most bioarchaeologists study not just individuals but entire populations to reveal biological and cultural patterns.
People have always been intrigued by the remains of the dead, however historically, human bodies were often studied isolated from the ground and location where they were found. Bioarchaeologists emphasize the context in and around where the remains are found, using a biocultural approach that studies humans through an understanding of the interconnectedness of biology, culture, and environment.
Forensic anthropologists use many of the same techniques as bioarchaeologists to develop a biological profile for unidentified individuals, including estimating sex, age at death, height, ancestry, or other unique identifying features such as skeletal trauma or diseases. They may also go to a crime or accident scene to assist in the search and recovery of human remains, aiding law enforcement teams (Figure 1.14). The popular television show Bones told the fictional story of a forensic anthropologist, Dr. Temperance Brennan, who brilliantly interpreted clues from victims’ bones to help solve crimes. While the show includes forensic anthropology techniques and responsibilities, it also includes many inaccuracies. For example, forensic anthropologists do not collect trace evidence like hair or fibers, run DNA tests, carry weapons, or solve criminal cases.
Forensic anthropology is considered an applied area of biological anthropology, because it involves a practical application of anthropological theories, methods, and findings to solve real-world problems. While some forensic anthropologists are academics that work for colleges and universities, others are employed by public safety and law agencies.
Many biological anthropologists do work that falls under the label of “human biology.” This type of research explores how the human body is affected by different physical environments, cultural influences, and nutrition. These include studies of human variation or the physiological differences among humans around the world. Some of these anthropologists study human adaptations to extreme environments, which includes physiological responses and genetic advantages to help them survive. Others are interested in how nutrition and disease affect human growth and development. Biological anthropologists engage in a wide range of research that spans the breadth of human biological diversity.
The six subfields of biological anthropology—primatology, paleoanthropology, molecular anthropology, bioarchaeology, forensic anthropology, and human biology—all help us to understand what it means to be biologically human. From molecular analyses of our cells to studies of our changing skeleton, to research on our nonhuman primate cousins, biological anthropology assists in answering the central question of anthropology: What does it mean to be human? Despite their different foci, all biological anthropologists share a commitment to using a scientific approach to study how we became the complex, adaptable species we are today.