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.
According to this model, modern humans evolved in East Africa, and started to disperse through the world roughly 50,000 to 100,000 years ago. The single-origin hypothesis is cited as having the scientific consensus as of the mid-2000s.