the reason why lucas and nathan can be the same age...
One Tree Hill
The Mystery: How can the half-brothers, Luke and Nathan, be exactly the same age?
The Answer: From creator and executive producer Mark Schwahn: "Alfred Hitchcock used to say 'Don't belabor the MacGuffin.' The MacGuffin was the thing that set everything into motion. Dan Scott and Karen Roe were high school sweethearts. Karen got pregnant in the summer after their senior year in high school. Dan chose to pursue his basketball dreams and accepted a scholarship offer, leaving Karen behind. Arriving at college, Dan met Deb. They began dating and a couple of months later, she was also pregnant. In the words of Karen, 'Dan always was an overachiever.' Perhaps because of the residual guilt of his abandonment of Karen, or perhaps because Deb was from money, from a big city, or simply seemed like his true love, Dan accepted this responsibility and married Deb. The following year, Lucas [Chad Michael Murray] was born in March. And in June, Nathan Lucas [James Lafferty] was born. The end."
http://www.eonline.com/Gossip/Kristi...3/031031b.html