Depression, addiction to tobacco and the risk of becoming a victim of a stroke - all these not very pleasant, but integral "properties" of our body have got to us from the Neanderthals, scientists have found out. The Science Department of Gazeta. Ru tells how Neanderthals worsened the health of modern people and why winter is the most harmful time of the year for women.
Modern man is partly due to his propensity to develop depressive disorders and the emergence of addiction to smoking Neanderthal - such conclusions were made by a group of American scientists led by John Capra from Vanderbilt University (Nashville, Tennessee, USA). Researchers have found out what effect the crossing of Homo sapiens with a Neanderthal had on the onset of depression. The study was published in the latest issue of Science.
Modern man left Africa and began to spread throughout Europe and Asia about 60 thousand years ago. Scientists assumed that Homo sapiens encountered archaic hominids, and genomic analyzes of the species Homo sapiens, Neanderthal man and Denisovan man ("Altai man") confirmed the presence of the same type of genes in these species.
The genome of a modern Eurasian can contain up to 4% of the DNA inherited from Neanderthals, mainly in the X chromosomes and the shoulder of the seventh chromosome.
The research team analyzed health data and genetic information from more than 28,000 Caucasian adults in the United States. Scientists used a set of 1,689 hierarchically related phenotypes identified using the International Classification of Diseases. Alleles of Neanderthals - different forms of the same gene - biologists were able to identify thanks to the genomic map of haplotypes (sets of alleles) of Neanderthals.
“Our main discovery is that we have learned:
Neanderthal DNA influences clinical disorders in modern humans. We have found links between Neanderthal DNA and a wide range of disorders, including immunological, dermatological, neurological, psychiatric and reproductive disorders,”comments John Capra.
As an example, the researchers cite the following discovery: Neanderthal DNA affects cells called keratinocytes, which help protect the skin from damage caused by environmental factors such as ultraviolet radiation. Some variants of Neanderthal genes interfere with the functioning of these cells, as a result of which the risk of developing keratoses, skin diseases characterized by keratinization and thickening, increases.
Promotional video:
A whole series of unexpected discoveries awaited scientists: it turned out that
Neanderthal DNA significantly increases the risk of nicotine addiction and depression, as well as other psychiatric and neurological disorders.
Another unpleasant "gift" we inherited from distant relatives is a gene that enhances blood clotting. For Neanderthals, it could be useful, as it helped not to lose a lot of blood when injured and injured. This gene is not good for modern people: it increases the risk of strokes, pulmonary embolism and complications that can occur during pregnancy.
John Capra's research group does not plan to stop there and is going to continue studying how genetic "gifts" from our distant ancestors can affect the health and life of a modern person.
However, it would be incorrect to say that depression and nicotine addiction are exclusively a legacy from the Neanderthals. Scientists have been interested in the cause of depression for a long time. Earlier, scientists from the University of Oxford found that the apathetic state, often accompanying depression, can be caused by the structure of the brain.
During the experiment, scientists invited a group of healthy volunteers to play a game in which it was necessary to use physical force and get a reward for it. During the assignment, the brains of the volunteers were examined using magnetic resonance imaging, and scientists made a paradoxical discovery. The projection zones of the cerebral cortex responsible for movement in apathetic people during the experiment showed greater activity than in purposeful people. The authors of the paper suggested that indifferent individuals need more effort to implement decisions and take action.
The work of the brain requires a significant expenditure of energy, and if apathetic people spend a lot of energy to plan an action, then there is no energy left to carry it out.
Another study found that women are more prone to depression during the winter than men. This is due, most likely, to the fact that the short daylight hours characteristic of winter causes hormonal disruptions in the body of women, which become the cause of depressed mood and aggressive behavior.