Archaeological research spans the entire development of phenomena that are unique to humans.
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.
Laetoli even reveals footprints of humans from 3.6 million years ago.
Some sites also contain evidence of the earliest use of simple tools.
With its focus on the ancient past, archaeology somewhat resembles paleontologythe study of fossils of long-extinct animals, such as dinosaurs.
However, archaeology is distinct from paleontology and studies only past human life.
Sites containing signs of the first simple but purposeful burials in graves date to as early as 40,000 years ago in Europe and Southwest Asia.
By the time people lived in civilizations, burials and funeral ceremonies had become extremely important and elaborate rituals.
Dozens of archaeological sites throughout Asia and Europe show how people migrated from Africa and settled these two continents during the last Ice Age (100,000 to 15,000 years ago).
Archaeological studies have also provided much information about the people who first arrived in the Americas over 12,000 years ago.
The earliest archaeological sites include those at Hadar, Ethiopia; Olduvai Gorge and Laetoli, Tanzania; East Turkana, Kenya; and elsewhere in East Africa.