Using many different pieces of evidence from all over the world, archaeologists, paleontologists, and other scholars have developed a view of human evolution that has a widely shared basic outline, though there are disagreements about details. Sometime between 7 and 6 million years ago in southern and eastern Africa, groups of human ancestors (members of the biological “hominid” family) began to walk upright, which allowed them to carry things. About 3.4 million years ago some hominids began to use naturally occurring objects as tools, and around 2.5 million years ago one group in East Africa began to make simple tools, a feat that was accompanied by, and may have spurred, brain development. Groups migrated into much of Africa, and then into Asia and Europe; by about 600,000 years ago there were hominids throughout much of Afroeurasia.

About 200,000 years ago, again in East Africa, some of these early humans evolved into Homo sapiens (“thinking humans”), which had still larger and more complex brains that allowed for symbolic language and better social skills. Homo sapiens invented highly specialized tools made out of a variety of materials: barbed fishhooks and harpoons, snares and traps for catching small animals, bone needles for sewing clothing, awls for punching holes in leather, sharpened flint pieces bound to wooden or bone handles for hunting and cutting, and slings for carrying infants. They made regular use of fire for heat, light, and cooking, increasing the range of foods that were easily digestible. They also migrated, first across Africa, and by 70,000 years ago out of Africa into Eurasia. Eventually they traveled farther still, reaching Australia using rafts about 50,000 years ago and the Americas by about 15,000 years ago, or perhaps earlier. They moved into areas where other types of hominids lived, interacting with them and in some cases interbreeding with them. Gradually the other types of hominids became extinct, leaving Homo sapiens as the only survivors and the ancestors of all modern humans.

In the Paleolithic period humans throughout the world lived in ways that were similar to one another. Archaeological evidence and studies of modern foragers suggest that people generally lived in small groups of related individuals and moved throughout the landscape in search of food. In areas where food resources were especially rich, such as along seacoasts, they settled more permanently in one place, living in caves or building structures. They ate mostly plants, and much of the animal protein in their diet came from foods gathered or scavenged, such as insects and birds’ eggs, rather than hunted directly. Paleolithic peoples did, however, hunt large game. Groups working together forced animals over cliffs, threw spears, and, beginning about 15,000 B.C.E., used bows to shoot projectiles so that they could stand farther away from their prey while hunting.

Paleolithic people were not differentiated by wealth, because in a foraging society it was not advantageous to accumulate material goods. Most foraging societies that exist today, or did so until recently, have some type of division of labor by sex, and also by age. Men are more often responsible for hunting, through which they gain prestige as well as meat, and women for gathering plant and animal products. This may or may not have been the case in the Paleolithic era, or there may have been a diversity of patterns.

Early human societies are often described in terms of their tools, but this misses a large part of the story. Beginning in the Paleolithic era, human beings have expressed themselves through what we would now term the arts or culture: painting and decorating walls and objects, making music, telling stories, dancing alone or in groups. Paleolithic evidence, particularly from after about 50,000 years ago, includes flutes, carvings, jewelry, and amazing paintings done on cave walls and rock outcroppings that depict animals, people, and symbols. Burials, paintings, and objects also suggest that people may have developed ideas about supernatural forces that controlled some aspects of the natural world and the humans in it, what we now term spirituality or religion. Spiritually adept men and women communicated with that unseen world, and objects such as carvings or masks were probably thought to have special healing or protective powers. (See “Evaluating the Evidence 1.1: Paleolithic Venus Figures.”)

Total human population grew very slowly during the Paleolithic. One estimate proposes that there were perhaps 500,000 humans in the world about 30,000 years ago. By about 10,000 years ago, this number had grown to 5 million — ten times as many people. This was a significant increase, but it took twenty thousand years. The low population density meant that human impact on the environment was relatively small, although still significant.