However, some people who have early-onset Alzheimer's don't have mutations in these three genes. That suggests that this early-onset form of Alzheimer's disease is linked to other genetic mutations that haven't been identified yet.
Early history Cigars, cigarettes Cancer by the carton Legal history Surgeon General's warning. (CNN) -- Tobacco was first used by the peoples of the pre-Columbian Americas. Native Americans apparently cultivated the plant and smoked it in pipes for medicinal and ceremonial purposes.
While who exactly was the first to smoke tobacco has been lost to history, Jordan Goodman, in his book Tobacco in History, theorizes that tobacco was first cultivated thousands of years ago in the Americas, around the regions that have become known as Mexico and Brazil.