Methods of dating archaeological sites
Archaeologists have also recorded how primitive forms of humans spread out of Africa into Asia about 1.8 million years ago, then into Europe about 900,000 years ago.
The first physically modern humans, Homo sapiens sapiens, appeared in tropical Africa between 200,000 and 150,000 years agodates determined by molecular biologists and archaeologists working together.
Archaeology became established as a formal discipline in the 19th and early 20th centuries.
At that time, most archaeological work was confined to Europe, to the so-called cradle of civilization in southwestern Asia, and to a few areas of the Americas.
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.
Other sites that represent great human achievement are as varied as the cliff dwellings of the ancient Anasazi (a group of early Native Americans) at Mesa Verde, Colorado (see Mesa Verde National Park); the Inca city of Machu Picchu high in the Andes Mountains of Peru; and the mysterious, massive stone portrait heads of remote Easter Island in the Pacific.
Today, archaeologists study the great cultural diversity of humanity in every corner of the world.
Archaeological study covers an extremely long span of time and a great variety of subjects.
The earliest subjects of archaeological study date from the origins of humanity.