Genetics may set internal clock

January 29, 2008 2:22:28 PM PST
Whether you are a lark or a night owl may be largely determined by your ancestors.

Scientists have found that each cell of the body has an internal clock which is affected by various genes. Research in the Proceedings of the National Academy of Sciences shows that skin test can actually be used to measure the speed of a person's body clock.

There is hope the discovery could lead to a better diagnosis of sleep disorders and conditions such as seasonal affective disorder, also known as SAD.