Studying the Distant Past Chapter 1 Section 1

Anthropology Anthropology is the study of how human beings behave, how they act together, where they came from, and what makes one group of people different from another. In this section, we will look at the work of a particular group of anthropologists, known as archeologists. Archeologists study human life in the past by examining the things that people left behind.

Study of Early Humans Learning about early humans is not easy. Until about 5,000 years ago, people had no way to write things down. To study, prehistory, or the time before written records, archeologists look for the places where people may have lived.

Hunting for Fossils To learn about the earliest humans, archeologists depend on fossils. Fossils are hardened remains or imprints of living things that existed long ago. These remains may include plants, feathers, bones, and even footprints that are a million years old. Fossils form in several ways. For example, after a living thing dies, it may quickly become covered with sand or mud. Once covered, the soft parts of the plant or animal rot away.

Hunting for Fossils The harder parts of a fossil, such as bones, teeth, or woody stems, last much longer. Over many years, minerals from soil slowly replace this once-living material. What remains is a rocklike copy of the original. Fossilized bones of early humans are rare. A complete fossil skeleton is even rarer. Fossil hunters usually find small pieces of bone and teeth.

Hunting for Fossils Studying a tooth can show what kind of food early people ate. Bones could tell us about the size and structure of the human’s body

Dating Ancient Remains Archeologists use several methods for determining the ages of fossils and other prehistoric objects. In this work, they get valuable information from geologists, scientists who study the physical materials of Earth itself, such as soil and rocks. One dating method is to compare objects found in similar layers of rock or soil. Objects found in lower layers are generally older than those found in upper layers.

Dating Ancient Remains Archeologists may also compare an object with similar fossil or artifact whose age is already known. Radioactive dating is another method for determining the age of very old objects. Both living things and rocks contain radioactive elements that decay, or break down, over time. By measuring the amount of radioactive material left, scientists can tell when an object was formed.

Dating Ancient Remains In recent years, scientists have developed other methods to study fossils. They us DNA to compare human remains from the past with people living today. Genetic evidence has uncovered new information about how people changed and how they moved from place to place.

Searching for Artifacts The earliest humans lived millions of years ago. To study prehistoric people who lived more recently, archeologists look for old settlements, such as villages or campsites. Such sites often lie buried beneath layers of dirt. Archeologists must carefully excavate, or uncover, these sites to learn about the people who once lived there.

Searching for Artifacts As archeologists dig up a site, they look for artifacts such as tools, pottery, or weapons. Artifacts are objects made and used by humans. They then try to identify patterns, examining what artifacts are found together in the same spot. Artifacts found in an ancient campsite can help archeologists understand how the people who once camped there hunted for food or what they ate.

Searching for Artifacts Some questions, however, are difficult to answer by studying artifacts. For example, archeologists excavating old campsites have found animal bones carved with strange designs. But they cannot explain why people created these fascinating artifacts.

The Hunt for Early Humans Where did people first appear on Earth? For a long time, scientists could not agree on an answer. In 1960, British archeologists Mary and Louis Leaky discovered a piece of human-like skull at Olduvai Gorge in East Africa. The Leakys called their find Homo habilis (Handy Man) because evidence showed that these early humans made and used tools. Tests showed that the Homo habilis fossils were at least 1.75 million years old. From that point on, the search for the origins of humankind has centered on Africa.

African Beginnings On November 30, 1974, American fossil hunter Donald Johanson made a discovery that helped shape how scientists view early human history. For three years, Johanson had been searching for evidence of early humans in Ethiopia, a country in East Africa. After two weeks, her team uncovered hundreds of pieces of bone. They determined that the pieces of bones came from one individual because they did not find two examples of any one type of bone. They determined she was a 3.5-foot-tall women. Johansen named her “Lucy.”

African Beginnings Johansen’s team found some 40% of Lucy’s skeleton. The bones of her legs, ankles, and spine suggest, like us, she walked upright on two legs. She lived 3.2 million years ago. Since Johansen’s discovery, even older fossils have been found in Africa. In 1992, American anthropologist Tim White found remains of humans who lived in Ethiopia at least 4.4 million years ago.

African Beginnings Beginning with a single tooth, White’s team uncovered more fragments. Finally in 2009, White unveiled a nearly complete skeleton of a female that he named “Ardi.” More than a million years older than Lucy, Ardi was taller and heavier. She probably walked upright, but slowly and awkwardly.

Search for the “Oldest One” Discoveries such as Lucy and Ardi have led most scientists to conclude that humankind began in East Africa about 4.5 million years ago. Not everyone agrees. Some argue that human life may have developed separately in different parts of the world. Others agree that human life started in Africa, but in a different region.

Search for the “Oldest One” French fossil hunter Michael Brunet is one of those who believes that human life started elsewhere in Africa. In 2001, Brunet found a brown, humanlike skull in the country of Chad. Tests showed the skull to be nearly 7 million years old. Brunet’s discovery has raised many questions. The skull found in Chad is more apelike than other early human skulls.

Search for the “Oldest One” Scientists will continue to look for answers to the common questions centered on Brunet’s discovery. Meanwhile, the search for ancient human fossils continues. “This is the beginning of the story,” says Brunet of his work in Chad, “just the beginning.”