First Civilizations

First civilizations
The first people who owned these features in the history of humanity were the civilizations of Mesopotamia, Egypt, India and China.

The first civilization that developed an urban system and a system of writing was that of Sumer, which was located in the area formerly known as Mesopotamia and now occupies Iraq. The early Sumerian cities like Ur and Uruk dating from 3500 BC.Later, around the year 3200 a. C. agglomerations appeared in the present territory of Egypt, on the banks of the Nile River to around the year 2500. C. urban systems have been detected in the Indus River valley in the Indian subcontinent, and China are indications of civilization in the year 1800 a. C. However, the distance between each of the civilizations we have just described, and littlecontact between them (Mesopotamia to Egypt, India and China), shared several characteristics:

These four civilizations were established on the banks of large rivers and grown in large river valleys, so the base of their economies were agriculture and livestock.

All these civilizations had major urban centers, in cases such as Mesopotamia and Egypt functioned as large complex political,commercial and religious.

Mesopotamia, Egypt, India and China developed hierarchical and stratified societies in strata classified according to their specialization. In these societies there was social mobility, as practiced strict respect for the traditions and heritage.

These four civilizations are known to possess enormous architectural monuments, which are mainly related to political power andspiritual and religious manifestations, such as the construction of cemeteries or cemeteries.

All these civilizations made great advances in the science, especially in the field of astronomy, mathematics and medicine. These advances were applied to the construction of his great monuments and works of public use.

These four civilizations were markedly slave and generally building theirarchitectural and engineering were performed using slave labor, which they obtained as spoils of his wars of conquest on less developed peoples.

Mesopotamia, Egypt, India and China are called as hydraulic civilizations built irrigation systems, due to the dependence of the rivers had to develop their agricultural activities and to ensure their survival.

First humans in America
There is also thetheory that Alaska hunters entered the continent chasing herds American the peopling of the Americas is the process by which the human species has spread in the Americas. Scientists have no doubt that humans are not native to America, so it was settled by people from elsewhere. Paleoanthropological evidence supports the hypothesis that humans arrived in the Americas from Siberia, in the northeastcorner of Asia.

From the point of view of the theory of the peopling late Paleoamericans entered the continent during the last Ice Age, which allowed passage to the New World via Beringia. This event occurred between 14,000 and 13,000 years A. P. Moreover, early colonization theory says that humans arrived in the Americas long before, based on the discovery of remains whose carbon-14 dating.Give older than 14,000 years that A. P. A paleoanthropological research adds information produced by genetics, which has served to reinforce some conjectures about the origin of the Americans.

In general, it is considered that the majority of Native Americans are descended from a single group from the northeast or eastern Asia. Speaking peoples Na-Dene are descendants of a second wave ofimmigrants who settled in North America, while the Eskimos arrived on the continent in the migratory flow more reciente.
After Paleoamericans entrasen the continent, passing Beringia was covered again by the sea, so that they were virtually isolated from the rest of humanity. Except for a brief Viking settlement on the coast of Canada and Greenland, there is no strong evidence to support a possible...