Saylor.org's Ancient Civilizations of the World/Origins of Neolithic Man
Modern Homo sapiens
By the start of the Neolithic Age around 10,000 years ago, modern humans or Homo sapiens sapiens had become the dominant primate species on the planet. Except for a few islands in the Pacific, humans had spread to every land in the world, from the highlands of the Himalayas to the Amazon basin. Hawaii would not be colonized until about 500 CE, while New Zealand would remain empty of human settlement until about 900 CE. Otherwise, humans were everywhere.
It is difficult to say just how culturally diverse humanity was, just at the end of the last Ice Age. The stone tools and small figurines called Venuses found at many early Neolithic sites suggest a remarkable uniformity of culture. However, humans tended to make stone cutting tools out of only four basic types of rock: chert, flint, obsidian and quartzite. The flaking properties of these stones lend themselves to particular shapes and forms quite well, but these prevent substantial differentiation in types. Some forms are sufficiently widespread and unique to be identified with specific cultures: the Clovis People of New Mexico, for example left behind spearpoints with a distinctive ogival shape and a thumb-shaped groove for binding the point onto a wooden spear half. A great many stone and bone tools, though, are anonymously uniform, carrying over their shapes from one generation to the next over thousands of years.
However, modern culture is not written in tools so much as in materials and gear that rot and decay. A young man in Europe and a young man in India and a young man in South America dressed very differently from one another in 5000 BCE, largely as a result of where they lived. Each spoke a different language from the others; each may have used similar tool sets, but one used that toolkit to hunt elk and moose, another to hunt cassowary, and another to hunt water buffalo. Each heard different stories from their elders, and wanted different things in life from one another. Each even had different standards of beauty when considering potential mates and marriage partners. In the same way, a Chinese woman, an Egyptian woman and a Mesoamerican woman learned to cook with different foods, and worked with different materials to clothe their families. They told their children different bedtime stories, played different games, and had different standards of beauty and ability when considering potential mates and marriage partners.
It is difficult to assess today what these ancient cultures looked like. However, by 4500 BCE the world was a patchwork of cultures. Some were gardeners, some were farmers, some were pastoralists, and some were hunter-gatherers. Some were straddling the dividing lines between methods of food production, and some people were actively traveling back and forth between different groups, carrying luxury food items, beads, precious stones and other goods between cultures, peoples and individuals. There were thousands of languages and millions of people world-wide. There may have been nations and kingdoms, but we know almost nothing about them, not even whether they existed. Writing was still more than a thousand years in the future.
"Ancient History/Human Evolution/Neolithic Age" (Wikibooks) http://en.wikibooks.org/wiki/Ancient_History/Human_Evolution/Neolithic_Age#Modern_Homo_sapiens_sapiens