Morning person? Thank Neanderthals.

About the episode

Genetic material from Neanderthals could explain why some, but not all, modern humans wake up early, researchers say.

It started with our ancestors about 300,000 years ago in Africa. About 70 thousand years ago, some of them moved to Eurasia, which includes all of Europe and Asia. These people were accustomed to the climate and daily rhythm of Africa and therefore had to adapt greatly in some places.

But other humans, such as Neanderthals, did live in Eurasia. Their ancestors had already arrived here 400,000 years ago and were genetically better adapted to the conditions.

There was also a great deal of genetic exchange between modern humans who came from Africa and humans who already lived on the Eurasian continent. This has enabled modern humans to adopt some genetic variations that are already adapted to circumstances.

Some of these adaptations have to do with pigment, but there is also a connection to the immune system, body fat distribution, and the ability to adapt to living in a cold, dry area. And with our biological clock, scientists now say.

They studied the relationship between genetic variants that came to us from Neanderthals and the sleep habits of hundreds of thousands of people from the UK Biobank, and found a link between those variants and being an morning person.

Other species that have had to adapt to colder regions with longer days show a similar shift toward earlier awakening. It is therefore not surprising that these Neanderthal traits are preserved in people living at high latitudes.

Researchers now prefer to study the same thing in people living in places other than England to see if a similar connection can be detected there.

Read more about the research here: Were Neanderthals morning people?