Early Humans: Source 1

Before Civilization

Human Ancestors

Prehistory is the large time period of history before humans developed writing or a written history. It is difficult to pinpoint the year when writing officially began, but sometime around 3500 BCE is when the first organized writing system appears (about 5500 years ago). Human prehistory is much larger since we have only been writing for the last 5,500 years.
Scientists and historians believe modern humans (that look like us) came from a long line of animals called hominids [HA-min-id] that slowly changed over time. Hominids are the group of primates (apes) that walk on two legs—this includes modern humans (yes, you are a primate). Over the last 3-5 million years, our ancestors gradually changed in size and appearance due to changes in their environment, diet, and lifestyle. These slow changes are called human evolution. The changes were very slow and small, but over 5 million years, small changes added up to major changes in our appearance.
Science allows us to find the age of fossils because all living things are made of carbon. We can find the date that carbon began to breakdown. Carbon begins to breakdown when living things die. So, we can find the age of bones, wood, cloth, or other plants if they turn into fossils. Radiocarbon dating allows us to date living things accurately up to about 50,000 years. Other elements beside carbon are used to date fossils up to 2.2 billion years old. The evidence shows modern humans (Homo sapiens) evolved in Africa about 200,000 years ago.
Intelligent Ancestors
About 2.5 million years ago, our ancestors learned to use stone tools—our first real sign of intelligence, compared to other animals. The use of stone tools began what is called the Paleolithic Age [PAY-lee-o-lith-ic] or Stone Age of human history. The Stone Age lasted for most of the last 2.5 million years as you can see below. The Stone Age ended when humans learned to take metal from rock (ore) and make metal tools. This began the Bronze Age. This occurred between 8,000 and 5,000 years ago (between 6000 BCE and 3000 BCE).

Our ancestors learned to control fire very early in some areas, but the evidence in most parts of the world shows hominids could control fire about 300,000 years ago. Fire allowed people to cook food, become healthier, and have a longer life. Fire also provided heat, light, and protection at night. Controlling fire was another sign of hominid intelligence.
Early humans lived in small tribes of hunter-gatherers. At this point in our history we were nomads. Nomads are people who stay on the move looking for food, without a permanent home. Many nomadic tribes may have moved only during the change of seasons as different foods became available. Finding food dominated this time in our history. Every day was a struggle to find enough food to feed the group. This prevented us from discovering new things, until the time when we didn’t have to worry about finding food each day.
Early Migration

Genetic [jen-E-tic] evidence—the DNA in our genes we pass down to our children—shows us clues about human migration. Africa was the only place on earth where modern humans lived until about 100,000 years ago. The last Ice Age began about 100,000 years ago, so we probably left Africa because of changing climate and environment. Some humans left Africa and moved into Southwest Asia (Middle East). Still most humans lived in Africa. Eventually, humans moved into Central Asia about 75,000 years ago and from there some went toward East Asia and others went toward Europe—they arrived about 40,000 years ago. When humans left Africa, there were at least 2 other human-like species they might have seen, shown on the map below.
The Americas were the last continents to be reached by humans—groups of people probably followed animal herds from Russia across the land bridge into Alaska. This group much later became Aztec, Inca, Maya, and Native Americans. The water level of the oceans was about 300 feet lower than today—this exposed ocean floor as new land. The water was trapped in massive glaciers that covered North America, Europe, and Asia. This was the last Ice Age. The last Ice Age ended about 10,000 years ago.
Our migration is shown by linguistic evidence too. Linguistics is the study of the structure and variety of languages and how they are related. We can trace the movement of people thousands of years ago by studying their genes and the language they speak today. For instance, we know many of the people living in India and Europe once lived in Central Asia together because their spoken languages today have similarities that shows they once had a common language.

As humans settled into new environments, they slowly developed unique appearances. Asian, African, and European people look different because they lived in different environments with different amounts of sun, wind, temperature, food, etc. The differences in environment created different adaptations, so the reason many humans look different today is because of at least 50,000 years of adapting to our different environments. Maybe 250,000 generations have passes in the last 50,000 years.
Early humans showed another major sign of intelligence about 35,000 years ago. Humans began to draw on the walls of caves—probably other places too, but it has been preserved in caves. Cave paintings often depict hunting scenes. This is some of the first artwork and also an early attempt at written communication.

https://sites.google.com/site/1ancientcivilizationsforkids/ancient-history-before-civilizations