Are you an early bird? A new study suggests one's genetic makeup, particularly genes inherited from Neanderthal and Denisovan ancestors, could be the reason behind your morning enthusiasm.
The intriguing research bridges humans' daily habits with our ancient past, showing a direct link between prehistoric genetics and modern sleep patterns.
The study, spearheaded by geneticist Dr. John Capra of the University of California, San Francisco, delved into the DNA comparisons between living humans and the genetic material from Neanderthal fossils. It emerged that Neanderthals shared specific clock-related genetic variants with modern humans who prefer waking up early.
In the study, Capra's team examined 246 genes related to the body's circadian rhythms. Officials discovered over 1,000 mutations unique to either modern humans or their ancient relatives. Many of these mutations had significant impacts on the operation of the body clock.
Using the UK Biobank database, which holds genomes and health data from half a million volunteers, researchers focused on the impact of the ancient genetic variants on modern humans. They found that nearly all ancient body-clock variants increased the likelihood of an individual being a morning person.
The correlation could be rooted in geography. Early humans lived near the equator with consistent day lengths, while Neanderthals and Denisovans adapted to higher latitudes with varying day lengths. The adaptation may have influenced their circadian rhythms, a trait possibly passed on to modern humans through interbreeding.
The study was published in the Genome Biology and Evolution journal.