Heart disease kills about a half-million people every year in the United States. It begins with the clogging of the arteries - which is called atherosclerosis. When there is too much saturated fat and trans fat in the bloodstream, it sticks to the walls, which narrows the passageway that blood must travel through.
The earliest known fossil of a human ancestor, a female Ardipithecus ramidus specimen nicknamed Ardi, is 3.2 million years old. Scientific evidence says that the first modern humans, Homo sapiens, appeared more than 200,000 years ago. Some fossils from the middle Pleistocene period (about 400,000 years ago), referred to as Homo sapiens rhodesiensis, may be archaic Homo sapiens - a transitional species.
The story of human evolution began in Africa about six million years ago and it describes the very long process that our ancestors went through to ultimately become modern humans.he fossils of these early hominids, which lived 2 to 6 million years ago, all come from that continent. Most scientists believe early humans migrated out of Africa into Asia between 2 million and 1.7 million years ago, entering Europe some time within the past 1 million years.