Archaeological studies have also provided much information about the people who first arrived in the Americas over 12,000 years ago.
Archaeologists concentrate their studies on past societies and changes in those societies over extremely long periods of time.
With its focus on the ancient past, archaeology somewhat resembles paleontologythe study of fossils of long-extinct animals, such as dinosaurs.
These sites contain evidence of the first appearance of bipedal (upright walking), apelike early humans.
Laetoli even reveals footprints of humans from 3.6 million years ago.
But unlike historythe study of written records such as government archives, personal correspondence, and business documentsmost of the information gathered in archaeology comes from the study of objects lying on or under the ground Archaeologists refer to the vast store of information about the human past as the archaeological record.
The archeological record encompasses every area of the world that has ever been occupied by humans, as well as all of the material remains contained in those areas.
Early domesticationthe planting and harvesting of plants and the breeding and herding of animalsis evident in such places as the ancient settlement of Jericho in Jordan and in Tehuacn Valley in Mexico.
Archaeology plays a major role in the study of early civilizations, such as those of the Sumerians of Mesopotamia, who built the city of Ur, and the ancient Egyptians, who are famous for the pyramids near the city of Giza and the royal sepulchers (tombs) of the Valley of the Kings at Thebes.
Because many items disintegrate over time, archaeologists get an incomplete view of the past that they must fill in with other kinds of information and educated reasoning.
On rare occasions, however, delicate objects have been preserved.
These include fossil remains believed to be of human ancestors who lived 3.5 million to 4.5 million years ago.