Elena Nikolaeva, doctor of biological Sciences, Professor of the Department of age psychology and family pedagogy of the Herzen Russian state pedagogical University, lecturer at the Imaton Institute, told how genes affect people's behavior.
Over the past 20 years, fantastic things have happened in neuroscience, which, unfortunately, are not implemented in our practical psychology, there are no popular books on this topic. So I wanted to tell you the most important discoveries that will be useful for understanding what happens to children.
In 2000, the human genome was discovered. Before that, a group of scientists gathered and they discussed how many genes a person can have. The Drosophila fly that flies over your grapes has 100 thousand. Perhaps a person should have more? It turned out to be 31 thousand. Three times less than Drosophila! The changes in the minds of scientists that occurred after understanding what the genome is, were tragic. In order to determine the genome, blood was taken from Nobel laureate Francis Crick, who discovered DNA. And when scientists looked at our DNA, they found that genes make up only 3% of our DNA!Over the past 20 years, fantastic things have happened in neuroscience, which, unfortunately, are not implemented in our practical psychology, there are no popular books on this topic. So I wanted to tell you the most important discoveries that will be useful for understanding what happens to children.
In 2000, the human genome was discovered. Before that, a group of scientists gathered and they discussed how many genes a person can have. The Drosophila fly that flies over your grapes has 100 thousand. Perhaps a person should have more? It turned out to be 31 thousand. Three times less than Drosophila! The changes in the minds of scientists that occurred after understanding what the genome is were tragic. In order to determine the genome, blood was taken from Nobel laureate Francis Crick, who discovered DNA. And when scientists looked at our DNA, they found that genes make up only 3% of our DNA!
We have 23 pairs of chromosomes. And about 5 million years ago, we separated from a common ancestor with chimpanzees. And I have to tell you with sadness that chimpanzees and we share 98.9% of the same genes. About 1% are the genes that separate us. One, the most important gene, is the one that was repeated 800 times and created our forehead. And the gene that transformed our pharynx, so we can talk. Everything else is the same.
A genome is a collection of all the genes of an organism contained in a haploid (single) set of chromosomes. Diploid organisms contain two genomes – the paternal and maternal. But each of you should remember the following amazing thing: Yes, indeed, we have paternal and maternal genes in the nucleolus, but, among other things, there are genes in the mitochondria. About 1.5 billion years ago, our eukaryotic cell captured a small bacterium that could produce energy. And then you decide for yourself whether it lives in the form of a slave or a warm friend, but in every cell there is a mitochondria that produces energy. How do we know she's not our own? Because we have rod-shaped chromosomes, and in the mitochondria lies the cyclic chromosome of a bacterium…
Conrad Waddington coined the word ""epigenetics"" in 1942. Why do we need this word? Since the bulk of textbooks in our country are reprints of the 80's, you can still read that scientists do not know what affects the child more: the external environment or genes. Scientists have long known, textbooks-have not yet learned. Thanks to the term ""epigenetics"", we can understand how parenting turns into altered genes in a child. And I will try to draw this picture for you.
DNA, genetics, and the closing or opening of the gene is epigenetics. Example: a grandmother smokes and her grandchildren will have diabetes. Only a grandmother will scold her daughter for bringing up children incorrectly, although the responsibility will lie with her. A very recent discovery: the genes that saved the blockade in our city, determine obesity and diabetes in their grandchildren. There is a closure of certain genes, which leads to changes in behavior and to changes in the functioning of the body.
How are genetics and epigenetics related? The problem is that we now know that we don't inherit genes – we inherit the norm of the gene's response, how the gene will respond under certain conditions. For example, we take a seed from a pine tree that stands on the shore of the Gulf of Finland, plant it in a small bowl, do not water it, and get a small tree. They have the same genetics, but the conditions of existence were different. Under certain conditions, the gene manifests itself completely, but under other conditions it does not manifest itself in any way.
How do genes close? Four bases are included in the nucleotides. Cytosine under certain conditions, for example, under stress or in the first 1.5 years of life, when no one approaches the child, is methylated, and a methyl group is attached to it. What does this lead to? Let's imagine that a child has just been born, and 20 thousand cells reappear in the brain. We give it to the children's home because the mother refuses it. The hormone cortisol is released (it is involved in the development of stress reactions), which should make the brain survive. And it closes all possibilities for restoration, reparations, and division. High levels of cortisol can cause the brain to not develop. Then the brain sends a signal to our genome in the gene of the receptor to cortisol. In order for the body to respond to cortisol, you need to have a receptor on the cell. The place where the enzyme sits to read is called the promoter. An enzyme sits on the promoter and the gene is read. When cortisol levels are high, the brain sends a signal, and a methyl group on cytosine sits on the promoter. And the enzyme slips. The gene closed.
The problem is that we know the mechanism, but there is not a single person in the world who knows, even theoretically, how this methyl group can be removed. And then in adolescence, when cortisol is released, but there are no cortisol receptors, the child resembles a car without brakes. You probably know that a large number of children were taken from orphanages after 2014. And now in some regions, 60% of children go back, because parents can't cope with children who were in an orphanage for the first 1.5 years. All sorts of stressful situations at different stages of a child's development lead to the methylation of certain genes, and this leads to a change in behavior.