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.
Homo sapiens (200,000 years-present) Modern humans evolved in Africa from a predecessor species known as Homo heidelbergensis. A small group of Homo sapiens left Africa 60,000 years ago and settled the rest of the world, replacing the other human species they encountered (with a small amount of interbreeding).