A genetic mutation called the "after-hours gene" may explain why some people are night owls, it is revealed in Science journal today.
The altered gene, named "after hours" or Afh, is a variant of a gene called Fbxl3, which had not been linked to the body clock that keeps our metabolism, digestion and sleep patterns in tune with the rising and setting of the sun.
The discovery involved scientists from the Medical Research Council Mammalian Genetics Unit, Oxfordshire, the MRC Laboratory for Molecular Biology, Cambridge, and colleagues based at New York University.
Told ya so! All my life I've struggled to achieve a "normal" wake/sleep cycle, finding it very unnatural for me. This may explain why.