Human Evolution

Although all of the ancestors described thus far first evolved in Africa, there is uncertainty as to where modern humans, Homo sapiens sapiens, first appeared. There are two theories to explain this process. The first is the "multi-regional" model, which proposes that Homo sapiens sapiens evolved in Europe, Asia, and Australia from Homo erectus after the latter left Africa about one million years ago. The second model, called Out of Africa, suggests that modern humans evolved only once, in Africa, leaving there within the last 200,000 years in a rapid global expansion. They replaced other populations of older human forms in Europe and Asia, including the Neanderthals. Variations and combinations of these two theories have also been proposed.

The oldest fossils of modern human beings, Homo sapiens sapiens, are 125,000-100,000 years old, appearing at the time of the first of the great ice ages. Homo sapiens sapiens are identified by a large brain (1,400 cc), a small face in proportion to the size of the skull, a small chin, and small teeth. In addition, they were tall and relatively slender in build.

The first fossil of modern Homo sapiens sapiens was found at Cro Magnon in France, which gave that name to all early Homo sapiens sapiens. Cro Magnon remains have been found along with the skeletons of woolly mammoth, bison, reindeer, and with tools made from bone, antler, ivory, stone and wood, indicating that Cro Magnon hunted game of all sizes. Cro Magnons also cooked their food in skin-lined pots heated with stones. Pieces of amber from the Baltic found in southern Europe together with Cro Magnon fossils indicate these humans traded material over vast distances. Cro Magnon humans buried their dead with body ornaments such as necklaces, beaded clothing, and bracelets.

Cro Magnon humans lived at the mouth of caves under shelters made of skins, or in huts made of sticks, saplings, stones, animal skins or even bones. A mammoth-bone hut 15,000 years old has been excavated at a site in the Ukraine. Anthropologists interpret some of the fossil findings of early Homo sapiens sapiens, by making comparisons with present-day hunter-gatherer tribes such as the Kalahari or Kung bushmen. These nomadic people live in relatively small bands of about 25 people. A larger group of about 20 bands makes up a community of people who all speak the same dialect and occasionally gather in large groups. The groups disperse into smaller bands during the wet season, and establish clusters around permanent water holes in the dry season. The men hunt in cooperative bands when the game is plentiful. The women gather plant material; about two thirds of their diet is made up of plant food. Since only a small portion of time is spent hunting or gathering, there is plenty of time for visiting, entertaining, and sewing. The same might be true for the hunting people living in Europe before 12,000 years ago.

Ice age humans were artists, producing hauntingly beautiful cave art. Carefully rendered pictures of animals, human and mythical representations, and geometric shapes and symbols were created using charcoal and other pigments. The remains of stone lamps found deep within these caves suggested that the caves were visited often. Carvings of stone, ivory and bone have also been discovered in these caves, including female figures. We cannot know what the significance of this art was to them, other than that it was a reflection of how early humans perceived the world around them.

The end of the ice ages brought changes in climate and ecosystems. In Europe, the vast grasslands were replaced by forests, and animal populations shifted from reindeer and bison to red deer and boar. The focus of cultural innovation shifted from Europe to the Middle East, where settled cultivation began.

There remain many unanswered questions. For example, Homo sapiens sapiens is the only species of hominid now existing. What happened to the preceding older species after the newer human form appeared and replaced it? How will Homo sapiens sapiens evolve in the future? Can humans consciously help to shape future evolution? Humans are the only species with the potential to consciously direct future evolution.