Editing Morning (section)

=== Genetics ===
For people, the morning period may be a period of enhanced or reduced energy and productivity. The ability of a person to [[wakefulness|wake up]] effectively in the morning may be influenced by a [[gene]] called "[[PER3|Period&nbsp;3]]". This gene comes in two forms, a "long" and a "short" variant. It seems to affect the person's preference for mornings or evenings. People who carry the long variant were over-represented as morning people, while the ones carrying the short variant were evening preference people.<ref>[http://news.bbc.co.uk/2/hi/health/6431971.stm Gene determines sleep patterns]</ref>