Researchers wonder why some people prefer mornings and others prefer nighttime. Is the preference born out of habit or is it biological?
According to a new study conducted by researchers at the University of Leicester, a person's biological clock, related behavior and inherent preferences are genetic.
In the study recently published in Frontiers in Neurology, researchers analyzed genetic variations in fruit flies. A fruit fly has a similar “genetic clock” to a human. In doing so, researchers identified nearly 80 variants possibly playing roles in one's sleep-and-wake preferences.
Researchers found the genes weren't more active at different times of the day as they previously believed. Instead, the entire genetic makeup of a fly that is active in the morning was different than the makeup of one that was more active in the evening.
Dr. Eran Tauber, one of the study's coauthors, explained,
[Looking] at the gene expression was only part of our research. An obvious question is what causes the different expression in the larks [early risers] and owls [late nighters]. This difference is largely due to genetic variations in their DNA sequences -- different gene versions that are present in larks and owls. The end point might be similar, but the different molecular routes result in a different journey time.
The researchers argue, given the findings, the nine-to-five structure is likely inefficient for many.
The study is pretty complicated and dense, but if you're interested, you can read more here.