Neanderthal Legacy: Early Risers May Inherit a Speedier Body Clock
New research suggests that genetic variants inherited from Neanderthals may increase the likelihood of being a morning person, supporting the theory that early risers have a faster body clock
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The study published Thursday in the journal Genome Biology and Evolution suggests that Neanderthals, who evolved at high latitudes in Europe and Asia for hundreds of thousands of years, may have been better adapted to seasonal variation in daylight compared with early Homo sapiens, or modern humans. While the human body clock is a complex trait shaped by social and cultural norms as well as genetics, early modern humans evolved in latitudes closer to the equator in Africa, where there's less variation in daylight hours.
DTFA4M Homo neanderthalensis, neanderthal man
The Natural History Museum/Alamy Stock Photo
Some groups of people have more Neanderthal DNA than others today, and a recent study provides insights into this phenomenon. The study suggests that early Homo sapiens may have inherited the adaptation to changes in daylight from Neanderthals as they migrated out of Africa and interbred with them. This genetic legacy could still impact variations in the human body clock and chronotype, determining whether an individual is a night owl or a morning lark.
Study coauthor Tony Capra, an associate professor of epidemiology and biostatistics in the Bakar Computational Health Sciences Institute at the University of California, San Francisco, who publishes research under the name John A. Capra, explained that at higher latitudes, it is advantageous to have a body clock that can more effectively anticipate and adapt to the changing seasonal light levels. According to Capra, individuals with a faster-running clock are more likely to rise early, as demonstrated by other species living across diverse latitudes whose circadian clocks adapt to differences in light/dark cycles.
The study involved researchers analyzing DNA from the standard human genome, its Neanderthal counterpart, and that of a Denisovan, another archaic human closely related to Neanderthals. Through comparing the genes that influence circadian rhythms in both archaic and modern DNA, they discovered several differences in how the circadian genes are linked to body clock function.
In order to determine if modern humans still possess Neanderthal genetic variants and their impact, researchers analyzed the UK Biobank - a medical database housing genetic and health data for a large number of individuals, including self-reported information on their sleep habits. "This allowed us to investigate whether remnants of Neanderthal DNA in current populations are more prevalent among early risers," explained Capra. "Our findings revealed that Neanderthal DNA resulting from interbreeding has a noteworthy impact. More specifically, the Neanderthal DNA linked to chronotype consistently enhances the likelihood of being a morning person."
On September 7, 2018, in Hamburg, Neanderthal researcher Svante Pääbo was honored with the European Science Prize by the Hamburg Körber Foundation for his groundbreaking contributions to the understanding of human origins. The prize, totaling 750,000 euros, was awarded to the 63-year-old physician and biologist from the Max Planck Institute for Evolutionary Anthropology in Leipzig. Pääbo's work has significantly transformed the knowledge of the evolutionary history of modern humans. Photo: Christian Charisius/dpa (Photo by Christian Charisius/picture alliance via Getty Images)
Christian Charisius/picture alliance/Getty Images
Ancient DNA hunter who sequenced first Neanderthal genome wins Nobel Prize for medicine
Since 2010, scientists have been researching the genetic variances between archaic and contemporary humans. The Neanderthal genome was first sequenced that year, leading to the discovery of the Denisovans from genetic sequencing of ancient DNA found in a fossil. These encounters between ancient humans and early Homo sapiens have left genetic imprints that are medically significant today. For instance, the EPAS1 gene, discovered to be a Denisovan version, provides a survival advantage at high altitudes and is prevalent among modern-day Tibetans.
Research has revealed that Neanderthal DNA could have a minor influence on the progression of Covid-19 infection. Additionally, a study released in June indicated a connection between Neanderthal DNA and Duputytren's disease, a condition characterized by abnormal tissue thickening in the hand.
