Where did our ancestors come from? Did humans originate all in one place, or did they evolve on several different continents simultaneously? Anthropologists argue over exactly where Homo sapiens made the evolutionary jump from primitive hominids to something closer to the humans we are today. However, most scientists subscribe to one of the following two theories.
The first is the multiregionalism theory (also known as the continuity theory), which states that apes evolved into humans on the continents of Africa, Europe and Asia. This theory would explain the fact that the peoples from each of these continents had distinct features due to genetic continuity in that particular area.
The more prominent theory, known as the out of Africa theory, or the replacement theory, holds that humans originated in Africa exclusively and then slowly migrated to the rest of the world, probably in two separate waves, somewhere between 56,000 and 200,000 years ago [source: The Economist]. While there were other hominids on other continents, they never evolved into humans. These early hominids may have died off because they couldn't compete with the more evolved Homo sapiens for the resources that were available.
Over the years, many studies have been conducted that support the out of Africa theory. For example, a group of Cambridge researchers examined the skull shapes of more than 50 human populations and discovered that the farther the population lived from Africa, the less genetically diverse it was [source: Sample]. This study, among others, supports the theory that Africa is the cradle of humanity, which is what most archaeologists have long believed.
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