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.
The Taung Child was killed by an eagle about three million years ago. Image courtesy of Wikicommons. If you know anything about human evolution, itâs probably that humans arose in Africa. But you may not know how scientists came to that conclusion.