Watch this CDC map change from 1985 to 2010 -and get more colorful along the way. It shows the percentage of people medically defined as obese. Obesity was once an odd condition, but for the U.S. it just gets more common every year. The Atlantic has a list of the metropolitan areas that have the lowest and highest rates of obesity. (However, moving to Colorado will only help if you are willing to climb mountains, hike, and ski.)
A family tree unites a diverse group of individuals that all carry genetic vestiges from a single common ancestor at the base of the tree. But this organizational structure falls apart if genetic information is a communal resource as opposed to a family possession.