Anthropology For Dummies. Cameron M. Smith
Skeletal anatomy: Because fossilized bone (bone turned to stone by a geochemical process) is the bread and butter of paleoanthropology, understanding how the body’s skeletal tissues reflect daily life, disease, stress, and other factors is critical to reconstructing ancient ways of life
Geology: Because fossils are often found in complex geological circumstances, such as fossil beds that contain the fossils of lots of plants and animals, perhaps millions of years extinct
Archaeology: Because archaeologists must exercise great care to excavate fossils, the principles of keeping track of where they find items and carefully bringing them back to the lab are important
Some people even specialize within these divisions; some paleoanthropologists focus on certain parts of the skeleton (like the teeth, the hand bones, or the pelvis), some focus on specific geological layers (for example, layers representing time before or after some event), and some focus on paleoecology, reconstructing entire ancient ecosystems in which early hominins evolved.
One of the main contributions of paleoanthropology to the human understanding of humanity is to fill in the missing links of the evolutionary chain connecting modern people to our most ancient ancestors. Unfortunately the term missing link is something of a misnomer because species aren’t so easy to define or draw lines around when you know them from fossil material only. But fossils do tell a lot about ancient life, and they do indeed show us, as a species, where we’ve been both figuratively and literally. (You can read more about fossils in Chapter 6.) Today, hundreds of fossil specimens bear some resemblance to modern people, and more ancient human-like forms. Because new species don’t pop up out of nowhere today, anthropologists can reasonably assume that these hundreds of fossils don’t represent early proto-humans that simply popped up and then vanished, either. Instead, they represent members of our own lineage that slowly changed over time by the evolutionary process. Fossil specimens are better thought of as shades from an evolutionary spectrum than links in a chain, but the chain metaphor has stuck, and it’s a tough one to fight.
THE KOOBI FORA RESEARCH PROJECT
Just two years into my undergraduate study of archaeology, I was lucky enough to participate in a field school at the Koobi Fora research project in northern Kenya. Run from the National Museum of Kenya and based on a landform called Koobi Fora on the eastern shore of Lake Turkana (once Lake Rudolf), the project was begun by Richard Leakey in the 1960s. Later it was run by his daughter, Dr. Louise Leakey.
Decades of research at Koobi Fora have revealed more than 200 early hominin fossils dating between about four million and 700,000 years ago. As a student, I vividly remember crawling across the baking desert and finding chips of stone eroding from an ancient lake-shore; picking one up, I realized it had been buried for more than a million years, and my career was locked in that moment.
Currently, George Washington University runs the field school in conjunction with the National Museums of Kenya; you can learn more at https://anthropology.columbian.gwu.edu/koobi-fora-field-school.
The fossils of the earliest human ancestors are in Africa so much of the fieldwork is done in countries with well-developed infrastructure (for example, roads and airlines) including South Africa, Kenya, Tanzania, and Ethiopia. Modern projects are normally large-scale, incorporating diverse international research teams that spend months in the field every year, on multi-decade projects. They commonly train African students as well, so that increasingly the authors of scientific reports on our past are Africans themselves.
The biocultural animal
One thing that makes physical anthropology particularly complex is that humanity evolves not only as a result of biological factors but also because of cultural factors. For this reason, anthropologists call it biocultural evolution. Culture — which I discuss more thoroughly in Chapters 2 and 11 — is basically the set of ideas that condition how you see and act in the world. Although humans survive by using both their biology and cultural information, all other animals survive mainly through their biology and by relying on instinct rather than such cultural information.
For example, cultural, not instinctual, information would have instructed you (if you were an early human) that certain kinds of wood are better than others for making a digging stick. You wouldn’t have known about different kinds of wood instinctually, but because detailed information about the properties of different kinds of wood was passed on to your mind culturally — through some form of language — by your parent generation or your siblings or others in your group.
IS THE HUMAN SPECIES STILL EVOLVING?
One of the most common questions asked of anthropologists is whether the human species is still evolving. Have we reached a pinnacle? Will we become giant-brained, fragile-bodied space-dwellers, using only a single finger to press buttons in the far future?
The simple answer is that yes, we’re still evolving; if we have offspring (replicate), if those offspring aren’t clones (variation), and if not all of our offspring survive to sexual maturity (selection), then by definition, the human species is evolving. But it’s natural to ask whether we’re still evolving because — in developed countries at least — humanity has used medicine and other means to eliminate a lot of the pressures that once took so many of our children. With so many selective pressures defeated (at least in the short term), you may easily conclude that significant genetic evolution has stalled in developed countries in the last century or so. Well, this is somewhat the case, although we continue to change genetically over time. But there is another way that we’re evolving, and its evolution is very rapid.
This other “channel” of our evolution is human culture, and this process is just as important as human genetic evolution. Human culture can change very rapidly, and the changes affect millions. Whereas we’ve had about the same size and shape of skull for 100,000 years, imagine the differences between the United States (say, in clothing and musical styles, concepts of race and religion, and the ethnic diversity of the population) in 1950 and the United States in 2020 — some pretty major changes occurred in the late 1960s (for example, the success of the civil rights movement), and in the past two decades we have had huge transformations in how we access information and interact socially. Whether the changes are good or bad is another matter; for the moment, the important idea is that yes, humanity is still evolving in a very significant way, sometimes very quickly.
This difference may seem trivial, but it’s actually very important. For example, consider the following cultural behaviors and their possible involvement with biological evolution of our species:
The earliest use of stone tools corresponds with increased consumption of animal tissues (for example, meat and organs). More animal tissue in the diet was only available by the use of stone tools, which were complex enough that young hominins would have to be taught a lot about them; that is the use of an increasingly complex culture to survive.
The use of clothing (itself a cultural artifact) allows human bodies to survive in environments they wouldn’t normally survive in. For example, the human body is naturally best-suited for equatorial environments, not the Arctic, but the invention of heavy coats and other such clothing enables that body to survive Arctic temperatures.
Paleoanthropologists are deeply concerned with understanding how cultural, noncultural, and biocultural evolutionary factors shaped humanity through time.
Considering that analyzing and understanding a single fossil skull can take years (in addition to what may have been an extensive search and excavation), it’s no surprise that