Another type of scientist that studies human history is an anthropologist. Anthropologists study humans and other human-like creatures known as hominids. They compare the bones of these creatures to one another, looking for changes in brain size and posture.
Mankind began keeping a written history about 5,500 years ago. Much of what we think of as human history happened between then and now. However, in reality this is just a scratch on the surface of human history.
Anthropologists and archeologists have traced human history back some 4.4 million years.