Biological anthropology is a sub-field that mediates the concept between human and animal and bio-cultural evolution. On the one hand, we are non-photosynthesizing, multi-cellular life – animals. On the other hand, we are a unique form of life that radically transforms its environment for survival. Bio-cultural evolution is a process that has occurred as a result of interactions between human culture, biological factors, and the environment throughout the history of human evolution.
Many biological anthropologists focus on the study of human evolution. Researchers who specialize in this area are called paleoanthropologists. These individuals search for fossil evidence of human evolution and construct theories of how, when, and why human beings first came into existence. By carefully comparing fossils from different sites and periods, paleoanthropologists have been able to trace our human origins back to Africa. They have also been able to document when our ancestors first began to develop distinctive human traits such as upright walking. Biological anthropologists often study differences in height, skin color, blood type, and other physical features in contemporary human populations, as well.
Some biological anthropologists also study monkeys, apes, and other primates. Humans share many behaviors and physical features with other primate species, including stereoscopic vision, grasping hands, an opposable thumb, and strong mother-child bonds. By observing primates in the wild, primatologists gain insight into our past. They can identify how certain primate behaviors or physical traits may have evolved by documenting their adaptive value. Strong mother-child bonds, for example, help ensure that more offspring will reach reproductive age. Therefore, this behavior is selected for in all primate species.
Another exciting area in biological anthropology is the study of forensics. Called forensic anthropologists, researchers in this area are often consulted on legal cases. Studies of human skeletal material can reveal important information such as sex, cause of death, nutritional deficiencies, and diseases suffered. This information is useful in establishing the identity of victims of homicide, natural disasters, genocide, or terrorism. As violence in our world increases, forensic anthropologists are increasingly called on to confirm reports of human rights violations. For example, they were able to determine that the Argentine military regime of the 1980s systematically killed many citizens who had “disappeared”. Forensic anthropologists were also instrumental in identifying victims of 9/11 in the United States.
When scientists discover a fossil skull, they compare it to skulls that have already been identified as particular early human species. Now you get to be the scientist!
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Bones contain evidence of how early humans lived, died, and interacted with other organisms. Explore what kinds of important clues scientists can find on bones.
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Explore our 3D collection of fossils and artifacts: view, rotate, and explore hundreds of 3D scans!
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Human evolution
Human evolution is the lengthy process of change by which people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people originated from apelike ancestors and evolved over a period of approximately six million years.
One of the earliest defining human traits, bipedalism -- the ability to walk on two legs -- evolved over 4 million years ago. Other important human characteristics -- such as a large and complex brain, the ability to make and use tools, and the capacity for language -- developed more recently. Many advanced traits -- including complex symbolic expression, art, and elaborate cultural diversity -- emerged mainly during the past 100,000 years.
Humans are primates. Physical and genetic similarities show that the modern human species, Homo sapiens, has a very close relationship to another group of primate species, the apes. Humans and the great apes [large apes] of Africa -- chimpanzees [including bonobos, or so-called “pygmy chimpanzees”] and gorillas -- share a common ancestor that lived between 8 and 6 million years ago. Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa.
Most scientists currently recognize some 15 to 20 different species of early humans. Scientists do not all agree, however, about how these species are related or which ones simply died out. Many early human species -- certainly the majority of them – left no living descendants. Scientists also debate over how to identify and classify particular species of early humans, and about what factors influenced the evolution and extinction of each species.
Early humans first migrated out of Africa into Asia probably between 2 million and 1.8 million years ago. They entered Europe somewhat later, between 1.5 million and 1 million years. Species of modern humans populated many parts of the world much later. For instance, people first came to Australia probably within the past 60,000 years and to the Americas within the past 30,000 years or so. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12,000 years.
Paleoanthropology
Paleoanthropology is the scientific study of human evolution. Paleoanthropology is a subfield of anthropology, the study of human culture, society, and biology. The field involves an understanding of the similarities and differences between humans and other species in their genes, body form, physiology, and behavior. Paleoanthropologists search for the roots of human physical traits and behavior. They seek to discover how evolution has shaped the potentials, tendencies, and limitations of all people. For many people, paleoanthropology is an exciting scientific field because it investigates the origin, over millions of years, of the universal and defining traits of our species. However, some people find the concept of human evolution troubling because it can seem not to fit with religious and other traditional beliefs about how people, other living things, and the world came to be. Nevertheless, many people have come to reconcile their beliefs with the scientific evidence.
Early human fossils and archeological remains offer the most important clues about this ancient past. These remains include bones, tools and any other evidence [such as footprints, evidence of hearths, or butchery marks on animal bones] left by earlier people. Usually, the remains were buried and preserved naturally. They are then found either on the surface [exposed by rain, rivers, and wind erosion] or by digging in the ground. By studying fossilized bones, scientists learn about the physical appearance of earlier humans and how it changed. Bone size, shape, and markings left by muscles tell us how those predecessors moved around, held tools, and how the size of their brains changed over a long time. Archeological evidence refers to the things earlier people made and the places where scientists find them. By studying this type of evidence, archeologists can understand how early humans made and used tools and lived in their environments.
The process of evolution
The process of evolution involves a series of natural changes that cause species [populations of different organisms] to arise, adapt to the environment, and become extinct. All species or organisms have originated through the process of biological evolution. In animals that reproduce sexually, including humans, the term species refers to a group whose adult members regularly interbreed, resulting in fertile offspring -- that is, offspring themselves capable of reproducing. Scientists classify each species with a unique, two-part scientific name. In this system, modern humans are classified as Homo sapiens.
Evolution occurs when there is change in the genetic material -- the chemical molecule, DNA -- which is inherited from the parents, and especially in the proportions of different genes in a population. Genes represent the segments of DNA that provide the chemical code for producing proteins. Information contained in the DNA can change by a process known as mutation. The way particular genes are expressed – that is, how they influence the body or behavior of an organism -- can also change. Genes affect how the body and behavior of an organism develop during its life, and this is why genetically inherited characteristics can influence the likelihood of an organism’s survival and reproduction.
Evolution does not change any single individual. Instead, it changes the inherited means of growth and development that typify a population [a group of individuals of the same species living in a particular habitat]. Parents pass adaptive genetic changes to their offspring, and ultimately these changes become common throughout a population. As a result, the offspring inherit those genetic characteristics that enhance their chances of survival and ability to give birth, which may work well until the environment changes. Over time, genetic change can alter a species' overall way of life, such as what it eats, how it grows, and where it can live. Human evolution took place as new genetic variations in early ancestor populations favored new abilities to adapt to environmental change and so altered the human way of life.
Evidence of Human Evolution.pdf
Dr. Rick Potts provides a video short introduction to some of the evidence for human evolution, in the form of fossils and artifacts.