Population explosion has made rare gene variants more common
Scientists from Cornell University (USA) and the University of California at Los Angeles, studying the genes of 14,002 people from all over the world, suddenly came to an unexpected and terrifying discovery. It turned out that humanity has acquired new, previously unseen mutations in recent years. And hereditary diseases, considered rare, began to spread everywhere.
- I knew that rare variants of altered genes appear today, but I had no idea that there would be so many of them! - admitted with surprise the lead author of the study, associate professor of the Department of Ecology, Evolutionary Biology and Bioinformatics at the University of California John Novembre (John Novembre).
And there was something to be amazed at: most of the surveyed had variants of genes that doctors had previously found from time to time. Thus, 10 621 people out of 14 002 examined were found to have at least one of 12 hereditary diseases that are not considered widespread. For example, the most famous are multiple sclerosis, bipolar mental disorder (a state that goes from manic to depressive and vice versa), schizophrenia, osteoarthritis and Alzheimer's disease. And only 3381 were healthy.
- Studies carried out fifty years ago showed that only one person in a thousand possessed a mutant genome, and now five people, - said John Novembre.
What is the reason? Previously, it was believed that genetic abnormalities arise from the off-scale radiation background around and the polluted environment teeming with mutagens. Today another attack has been added to them. Overpopulation.
“The higher the population growth, the more mutations appear in the gene pool of mankind,” explains study leader Dr. Matthew Nelson. “Indeed, over the past ten thousand years, the number of people has grown from several million to seven billion. Moreover, the greatest acceleration has occurred over the past two thousand years, or over the last hundred generations. Indeed, with the advent of agriculture and the industrial revolution, human existence has become comfortable and safe. And among the billions, the transfer of chromosomes from parents to children occurs easier and faster, and there are more opportunities for mutations in the genome.
As a result, rare variants of genes became more common. And scientists do not exclude that new types of mutations may soon appear, which will lead to unknown changes in the human body.
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Some researchers have even tried to dream up about "mutants". So the assistant professor at the University of California Darren Kessner (Darren Kessner) suggested that among earthlings will soon appear fantastic "X-Men." They will not come out of secret laboratories, as in the famous blockbuster, but will be born naturally.
OPTIMIST'S OPINION
Candidate of Medical Sciences, Associate Professor at the Institute of Medical Genetics, the author of the book "Mutations, or How Do Malignant Genes" appear Alexander PRYTKOV:
- Genes have the ability to change, acquire new properties. This is called mutations. And it is gene mutations that create the variability necessary for the evolution of living matter, the diversity of life forms.
The reasons for their occurrence are in many environmental factors with which each organism interacts. These are both ionizing radiation and chemicals.
It is obvious that mutations have always existed as a completely common natural phenomenon. But some - useful - are fixed in the course of evolution. Others - harmful - underlie hereditary diseases. And the number of such diseases is growing every year. Perhaps this trend will continue in the future. However, it is possible that it reflects an improvement in the recognition of hereditary diseases and a closer attention to them than a real increase in their number in the process of evolution.
