Can being a night owl actually be scientific, and *not* just someone not bothering to change their schedule?

I'm such a night owl. Insanely so, and I came across an article that says that your genes can actually predispose you to such things. Does anyone know if this is true? I really am unable to live all that well during the day. My skin is so sensitive that if I am in the sun for too long(which doesn't take long), even with sunscreen and long sleeved shirts, I can develop painful rashes, and I get migraines from the sunlight. I also tend to develop depression from being off what I consider to be my "natural" sleep schedule, so I would like to know if humans can actually naturally be nocturnal. Please help me out with any info you might have!