The Genetic Answer
Upon researching, scientists found that variations to particular gene dubbed PER1 which is part of a group that affects circadian rhythms, are also affecting circadian timing.
Research indicates that 60% of today’s population has a variant called Adenine. We will call this variant (A). 40% of today’s population houses a variant called Guanine. This we will call (G). The A variant is responsible for waking up early so to speak. While this G variant, is responsible for preferring to wake up later.
Remember that each human carries a DNA double helix. This means that each of us has two sets of DNA chromosomes. Further investigation concludes the following.
Early Birds: two As will be found in 36% of people
Night Owls: two Gs will be found in 16% of people
In Between: both A and G will be found in 48% of people
Experiments involving test subjects concluded that individuals that carried a double (A) gene variant, were considered to be the early birds; And woke up just about 60 minutes earlier than individuals who possessed a double (G) gene variant. Leaving the last group, those with a combination of both an (A) gene variant and (G) gene variant seem to linger somewhere in between. While the times were not consistent, they did tend to stay near the meridian of both.
Other Implications for The Circadian Gene
The circadian rhythms are not only affecting the timing of our sleeping patterns, they also affect the timing of when individuals may die. These same (A) and (G) gene variants are also present when researching deaths, by time of day in individuals.
Research has even shown that individuals with genotypes of (AA) and (AG) are most likely to die during the early morning, around 11 AM. However individuals with a (GG) genotype have a much higher tendency to pass away during later times of day, around the 6 PM timeframe.