6 How do atoms absorb & emit light? â¢ Key idea: Energy â¢ A photon carries energyâ¢ Electron in orbit has energy because it is moving and it is pulled by nucleus. â¢ When atom absorbs photon, energy of photon promotes electron to higher energy.
Until now, researchers believed that homo sapiens, the direct descendants of modern man, evolved in Africa about 200,000 years ago and gradually migrated north, through the Middle East, to Europe and Asia.
It suggests that modern humans originated in Africa within the last 200,000 years from a single group of ancestors. Modern humans continued to evolve in Africa and had spread to the Middle East by 100,000 years ago and possibly as early as 160,000 years ago. Modern humans only became well established elsewhere in the last 50,000 years. The âOut of Africaâ model has had a variety of names including: âThe Garden of Edenâ hypothesis.