Latest findings shed more light on Out of Africa theory
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Our ancestors were attracted to a green, prehistoric Arabia
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- The story: The story of mankind is an amazing tale of adventure, moving out and exploration. The world as we see it today, was not so, millennia ago.
- Findings: Extensive excavations have revealed stone tools from multiple periods of prehistoric settlement by early human groups, the oldest 4,00,000 years ago.
- The desert regions of Arabia were once intermittently lush and green, attracting early humans and large animals such as hippopotamuses migrating out of Africa to linger at ancient lakes
- Until 2010, the Arabian Peninsula was a blank spot on the map for scientists trying to reconstruct the story of early human evolution and movements out of Africa. Much more is known about early human settlements in the Levant region — modern-day Israel, Jordan, Lebanon and parts of Syria — where extensive archaeological research has been carried out for more than a century.
- Arabia has not been part of the story of early human migration because so little work was done there before
- Satellite imagery showed the way: The impetus to look closely for archeological remains in the region came from satellite imagery that revealed traces of prehistoric lakes in now-arid regions. Scientists noticed color patterns made by ancient lakes — sand dunes are kind of orange-colored, while ancient lakes are tinted white or gray.
- Analysis of sediment samples from the ancient lakes and remains from hippos and other animals revealed that during several periods in the distant past, the peninsula hosted year-round lakes and grasslands.
- During these windows of hospitable climate, early humans and animals moved from northeast Africa into the Arabian Peninsula, the researchers say.
- Flowing rivers and lakes, surrounded by grasslands and savannah, would have attracted animals and then the early humans that were in pursuit of them. Hippos require year-round water bodies several yards (meters) deep to live. Remains of other animals, including ostriches and antelopes, indicate “a strong biological connection to northeast Africa.
- Learning: What this research did was to combine archaeology and climate records going back 4,00,000 years to show that early humans moved across this landscape when the climate changed. The episodic presence and absence of populations in the Arabian Peninsula was in tune with climate oscillations.
- Knowledge centre:
- Out of Africa theory - The first theory tracing the origins of modern man is the 'Out of Africa' model. It states that Homo sapiens developed first in Africa and then spread around the world between 1,00,000 and 2,00,000 years ago, superseding all other hominid species. The implication of this argument is that all modern people are ultimately of African descent. The other theory, known as the 'Multi-regional' Model, is that Homo sapiens evolved simultaneously in different parts of the world from original Homo erectus settlers. This means that people in China descended from the Homo erectus population there, while Australians may have descended from the Homo erectus population in South East Asia.
- Homo habilis - Homo habilis, known as 'handy man' is a species of the genus Homo which lived from approximately 2.33 to 1.4 million years ago, during the Gelasian Pleistocene period. He is one of the earliest known humans in Eastern and Southern Africa.
- Homo erectus - The extinct ancient human Homo erectus is a species of firsts. It was the first of man's relatives to have human-like body proportions, with shorter arms and longer legs relative to its torso. It was also the first known hominin to migrate out of Africa, and possibly the first to cook food. H. erectus was also the most geographically widespread species apart from H. sapiens. H. erectus appeared in Africa about two million years ago, evolving from either a late form of australopith or one of the more primitive forms of Homo, and went on to spread into many parts of Asia.
- Homo sapiens - All people today are classified as Homo sapiens. This first began to evolve nearly 2,00,000 years ago in association with technologies not unlike those of the early Neanderthals. It is clear that early Homo sapiens, or modern humans, did not come after the Neandertals but were their contemporaries. Compared to the Neanderthals and other late archaic humans, modern humans generally have more delicate skeletons. The skulls are more rounded and their brow ridges generally protrude much less. They have relatively high foreheads, smaller faces, and pointed chins.
- EXAM QUESTIONS: (1) Explain how the evolution of humans over the past 25 lakh years changed planet Earth. (2) How can science reconcile climate change (over the millennia) with archaeological findings, to arrive at definite conclusions?
#History #HomoSapiens #HomoHabilis #Neanderthals #OutOfAfrica #Archaeology
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