-How climate and environment shaped human migration and cultural development
-Regional differences between indigenous groups
-Ways in which agriculture promoted the development of population centers
-Conditions leading to the Sub-Saharan slave trade

[SLIDE 1]

What became known to Europeans as the New World was "new" only because it had previously been so isolated. To trace that isolation, we must go back as far as the Pleistocene Epoch to a time when there were a series of glacial and interglacial climatic periods commonly known as "the Ice Age." Glaciation, the creation of vast ice sheets, produced a drop in sea levels. This meant that shifting landforms were created in what had previously been seas. The land called Beringia formed a land bridge, a migratory path between what today is Siberia in northeastern Asia and northwestern Canada/Alaska.

[SLIDE 2]

Scientists use a combination of geological studies, climate studies, archeological discoveries, genetic investigations, and linguistics to reconstruct our picture of how human migration occurred. The information is subject to frequent revision as new data becomes available.
The dates of the Bering Land Bridge are based on global sea level estimates. Researchers still debate how and when the earliest migrations took place, whether inland through an ice-free land corridor or by hugging the coastline.

Whatever the migration routes, genetic studies show that early Beringians became genetically isolated from other East Asians. Although it's not certain when they arrived in the Western Hemisphere, by 9,500 BCE, humans had settled the length of North and South America.

[SLIDE 3]

The picture of Native American ancestry is still evolving, so this description is only provisional. It is based on the idea of multiple waves of migration. It is clear that the people who became the earliest Native Americans had split from the East Asian genetic population, perhaps while living on Beringia, by around 25,000. These Ancient Beringians, or Paleo-Indians, were the first settlers of North America, followed many thousands of years later by the Na-Dene, and still later by the Eskimo-Aleuts. Mingling of these three groups over a long period of time resulted in a diversity of Native American peoples.

[SLIDE 4]

As temperatures warmed and the great Ice Age mammals became extinct, approximately 9,000 years ago, new characteristic patterns of life emerged based on the changed environment. Tree trunks were hollowed to make boats; domesticated dogs were used to carry loads. Movement from camp to camp allowed for seasonal food gathering. Forest clearing encouraged the growth of desirable food plants. Grass grains like maize were developed from small seeds into larger grain nutritious crops.

[SLIDE 5]

Nutritional crops were encouraged and developed, becoming the basis of the Native American diet. Reliable, nutritional food crops allowed for more settled life so that larger villages capable of supporting larger numbers of people could develop. Eventually, much of Native American agriculture would be based on the Three Sisters: corn, squash, and beans.

[SLIDE 6]

The three crops known as the Three Sisters originated in Mexico and were brought north, where over time they formed a staple diet for many tribes in North America. Domestication of these crops took many thousands of years. 

[SLIDE 7]

Successful agriculture led to a more sedentary lifestyle for some. Around 3,000 years ago, throughout the Ohio and Mississippi Valleys population centers developed. The people who created these cities are known to us as Mound Builders. These elaborate cities served as centers of trade and ceremony. The people who built these mounds are believed to be the ancestors of many later, better-known tribes. The reason these sites were abandoned is unknown.

[SLIDE 8]

Because of the complexity of the Native American cultural landscape, historians cluster them in groups according to regions and similarities. The Indian nations were well established in their own distinct territories by the time Europeans began arriving.

[SLIDE 9]

The southeast and northeast comprised two different cultural groups, each with its distinctive traits and lifestyles.

[SLIDE 10]

Gendered division of labor among the Iroquois went back to hunter-gatherer days.
Women's traditional role dealt with collecting and processing plants. As agriculture rose in importance, so did the status of women.

[SLIDE 11]

Lifestyles of specific groups included adaptations to local conditions.

[SLIDE 12]

Regional circumstances sometimes necessitated new adaptations. Climatic conditions figure large in the work of researchers trying to explain migration and settlement patterns.  A medieval climate shift in Western North America prompted important adaptations by the residents of the Southwest.

[SLIDE 13]

One example of successful adaptation to climate is the case of the Ancestral Pueblo, who were the pre-Columbian forebears of modern Pueblo tribes like the Zuni and Hopi. (Pre-Columbian refers to the time before Columbus and European colonization.) Examples of the complex architecture built by these ancestral Pueblo people can still be seen today in the Four Corners area of the Southwest; namely, Colorado, Utah, Arizona, and New Mexico. These Ancestral Pueblo are also known as the Anasazi. That name is not generally acceptable to today's Pueblo peoples since it was given to them by the rival Navaho and means "ancestors of the enemy.” The Ancestral Pueblos developed from a migratory people into one reliant on crops, becoming sedentary in the process and developing sophisticated methods of water control to improve crop success in a difficult climate. Although the primary domestication of turkey occurred in central Mexico, recent evidence suggests that a second site of domestication occurred in the Southwest.

One group of Southwestern Indians abandoned the area and migrated south into Mexico, becoming the Aztecs.

[SLIDE 14]

Early Ancestral Pueblos are called the Basketmakers by historians because of their sophisticated ability in weaving baskets, a skill they developed in the Hunting and Gathering stage. Over time, the early people became more reliant on crops and became more sedentary, moving into what historians term the Pueblo stage. The exact reasons for the decline of this civilization are unknown, but archeological investigation of some sites has revealed disturbing evidence of massacres. 

[SLIDE 15]

A different climate adaptation was made by the people who became the Aztecs. They migrated away from the difficult conditions of the Southwest and settled in the Valley of Mexico, where they came to dominate the region.

[SLIDE 16]

Both the Navajo and the Apache migrated to the Southwest region from the north. Under the influence of the indigenous Pueblo peoples, the Navajo would become settled agriculturalists. Their cousins the Apache, however, would remain hunter-gatherers.

[SLIDE 17]

Some tribes did not rely on agriculture, because it was either unfeasible where they lived or unnecessary. Such groups continued the ancient ways of hunter-gatherers. Social organization varied according to the region. In the case of the Nez Perce, groups would come together to share labor and harvest specific resources. Leadership shifted according to who was best able to accomplish the task. Such temporary groups would then disband
[SLIDE 18]

In a tragic bit of historical irony, settlement of the New World by Native Americans made possible the later conquest of the North and South America by Europeans.

[SLIDE 19]

During classical antiquity, trade had existed between the Mediterranean world and Africa, but the process of desertification isolated much of Africa from the Mediterranean coast.

[SLIDE 20]

 Climate change caused important changes in the civilization of Sub-Saharan Africa. People in Sub-Saharan Africa were forced to abandon earlier lifestyles and adapt to much drier, harsher conditions because of the process of desertification.

[SLIDE 21]

Social organization was based on the notion of fictive ancestors, mythic founding figures from whom separate groups are descended and which provide a stable connection between these groups.
[SLIDE 22]

Bonded labor was part of the economic structure of Sub-Saharan Africa. The nature of slavery varied in different parts of Africa, but slaves often had certain rights and protections and could in some cases achieve respected, higher status roles. Slavery and labor exploitation continue to plague Sub-Saharan Africa today.

[SLIDE 23]

Raw iron was plentiful in Africa. The development of iron smelting techniques formed the basis of African trading centers and the growth of cities. Islamic expansion out of Arabia provided a boon in the form of trading partners and the creation of a trans-Saharan trade using camels for transport across the desert. Trans-Saharan trade brought about the growth of wealthy African states. Silks and spices brought by Muslim traders were exchanged for African products: iron, gold, gems, and slaves.