Rise & Shine: Neanderthal DNA May Explain How Some Folks Are Early Birds

A recent study reveals a fascinating genetic connection between modern early risers and their ancient Neanderthal and Denisovan ancestors, suggesting human sleep patterns may be influenced by the genes inherited from prehistoric relatives.

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.

Neanderthals and their eastern cousins, the Denisovans, diverged from the human lineage around 700,000 years ago. While humans mostly remained in Africa, Neanderthals and Denisovans ventured into Eurasia.

As modern humans later migrated out of Africa, interbreeding occurred, leading to the integration of Neanderthal and Denisovan DNA into the human gene pool.

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.