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.
Earliest human migrations and expansions of archaic and modern humans across continents began 2 million years ago with the migration out of Africa of Homo erectus. This was followed by the migrations of other pre-modern humans including H. heidelbergensis, the likely ancestor of both modern humans and Neanderthals. Finally, Homo sapiens ventured out of Africa around 100,000 years ago, spread across Asia around 60,000 years ago and arrived on new continents and islands since then.