In about one out of every 800 people, two chromosomes fuse together to form an unusual bond. These are known as Robertsonian chromosomes. It's a mystery that has long stumped scientists.

The Diamondbacks came from behind to walk off the Dodgers, 5-4, in the ninth inning Tuesday night and keep alive their hopes of capturing the final NL Wild Card spot. The win, combined with the Mets' ...