The Neanderthal heritage influences psyche and skin

Neanderthal genetic material influences properties such as skin tone and hair color of living people today
It's more than just skin color. Scientists from the Max Planck Institute for Evolutionary Anthropology in Leipzig have uncovered in a study that Neanderthal genes influence our mood and our biorhythm. So they affect whether we are "night owls" or smoke. As the researchers further report, these archaic genes can even influence how our skin tans, whether we tend to be indifferent or tend to isolate ourselves socially. The various subjects accumulated certain Neanderthal genes.

When humans and Neanderthals met thousands of years ago, both species began to mix. Therefore, about two percent of the DNA of today's non-African people come from them. Recent studies have shown that some of these Neanderthal genes still influence the immune system today and contribute to modern diseases. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig have now discovered that our Neanderthal heritage also affects other properties, including skin tone, hair color, sleep, mood, and even whether a person smokes or not.

Great progress in the study of human genes. Picture: anibal - fotolia

Inspired by a previous study in which researchers have discovered that Neanderthal DNA in the genetic makeup of modern humans affects the risk of certain diseases, Kelso and her team at the Max Planck Institute for Evolutionary Anthropology have investigated further properties in modern humans. Because Neanderthal DNA is relatively rare in the human genome, scientists had to analyze data from a variety of people. They found them in the more than 112,000 participants in the British "UK Biobank" pilot study. The database contains genetic information as well as information on, among other things, appearance, nutrition, sunlight, behavior and diseases.

"We can now show that especially the skin tone, the ease with which one tans, and the hair color of Neanderthal DNA are affected," says Kelso. The researchers studied Neanderthal DNA in modern humans, contributing to skin tones and hair colors. Surprisingly, some Neanderthal variants are associated with lighter skin tones, others with darker skin tones. The same goes for the hair color. "These results may indicate that Neanderthals had different hair colors and skin tones, as do people today," says lead author Michael Dannemann.

Furthermore, the researchers found that Neanderthal DNA also affects mood, smoking and sleep patterns. For example, people with certain types of Neanderthals are on average smokers more frequently, while other Neanderthal DNA is more often found in "night people." Many of these characteristics are related to solar radiation. When modern humans arrived in Eurasia about 100,000 years ago, the Neanderthals lived there for several thousand years. They were probably better suited to lower or changing levels of ultraviolet solar radiation than the humans who had just immigrated from Africa.

"Skin and hair color, biorhythms and mood are all influenced by the sunlight," the researchers said. "We therefore think that this could have contributed to the emergence of the various Neanderthal phenotypes and continues to contribute to the variation of these properties in today's living people through gene flow." (Sb)