Until recently, the earliest human hearths were dated to about , B. He acknowledges that this is a problem for his theory. But the number of sites dating from that early period is small, and the evidence of fire might not have been preserved. Future excavations, he hopes, will settle the issue. Fire detoxifies some foods that are poisonous when eaten raw, and it kills parasites and bacteria.
Again, this comes down to the energy budget. Animals eat raw food without getting sick because their digestive and immune systems have evolved the appropriate defenses. Presumably the ancestors of Homo erectus —say, Australopithecus —did as well. But anything the body does, even on a molecular level, takes energy; by getting the same results from burning wood, human beings can put those calories to better use in their brains.
Fire, by keeping people warm at night, made fur unnecessary, and without fur hominids could run farther and faster after prey without overheating.
Fire brought hominids out of the trees; by frightening away nocturnal predators, it enabled Homo erectus to sleep safely on the ground, which was part of the process by which bipedalism and perhaps mind-expanding dreaming evolved. By bringing people together at one place and time to eat, fire laid the groundwork for pair bonding and, indeed, for human society.
We will now, in the spirit of impartiality, acknowledge all the ways in which cooking is a terrible idea. The demand for firewood has denuded forests. As Bee Wilson notes in her new book, Consider the Fork , the average open cooking fire generates as much carbon dioxide as a car. Indoor smoke from cooking causes breathing problems, and heterocyclic amines from grilling or roasting meat are carcinogenic.
Who knows how many people are burned or scalded, or cut by cooking utensils, or die in cooking-related house fires? How many valuable nutrients are washed down the sink along with the water in which vegetables were boiled? Cooking has given the world junk food, course tasting menus at restaurants where you have to be a movie star to get a reservation, and obnoxious, overbearing chefs berating their sous-chefs on reality TV shows. Raw-food advocates are perfectly justified in eating what makes them feel healthy or morally superior, but they make a category error when they presume that what nourished Australopithecus should be good enough for Homo sapiens.
For instance, people first came to Australia probably within the past 60, years and to the Americas within the past 30, years or so. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12, years.
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 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. 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. 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 , years. The beginnings of agriculture and the rise of the first civilizations occurred within the past 12, years. Smithsonian anthropologists research many aspects of human evolution around the globe, investigating fundamental questions about our evolutionary past, including the roots of human adaptability.
For example, Paleoanthropologist Dr. Rick Potts — who directs the Human Origins Program — co-directs ongoing research projects in southern and western Kenya and southern and northern China that compare evidence of early human behavior and environments from eastern Africa to eastern Asia. Rick describes his work in the video Survivors of a Changing Environment. Briana Pobiner is a Prehistoric Archaeologist whose research centers on the evolution of human diet with a focus on meat-eating , but has included topics as diverse as cannibalism in the Cook Islands and chimpanzee carnivory.
Her research has helped us understand that at the onset of human carnivory over 2. She uses techniques similar to modern day forensics for her detective work on early human diets. Paleoanthropologist Dr.
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