http://www.britannica.com/science/human-evolution#toc250594 https://www.britannica.com/science/human-evolution http://www.britannica.com/science/human-evolution Encyclopaedia Britannica: Human evolution Evolution Article image from Britannica.com Evolution of Human Beings human evolution | Stages & Timeline | Britannica.com Encyclopaedia Britannica: Human evolution image from Britannica.com https://www.britannica.com/science/human-evolution image from Britannica.com Encyclopaedia Britannica: Human evolution