6 myths about genes that scientists have long refuted

1. Genetically, a person is closest to a pig

While the misconception does not sound very logical, it is quite widespread. The myth probably appeared because the internal organs of pigs can potentially be transplanted to humans. These animals do not have certain proteins that would trigger a reaction from the immune system, so our body is likely to mistake the implanted organ for its own. And that will take root easier and more successfully. In theory, the process should go even better if the pig is genetically modified.

However, this does not mean that our DNAs are very close. The genetic code largely determines evolution: it is most similar in animals of the same order, family, genus and species. The closest relatives of humans are primates, especially chimpanzees. The latter's DNA is particularly reminiscent of ours.

2. Genes determine everything

In fact, their influence is not absolute. For example, the personality traits of the Big Five depend on heredity by only 40-60%.

The same can be said for mental abilities. There have been many experiments in which scientists have tried to discover whether intelligence is inherited or not. And none of the experiments showed a clear relationship between the mind and genes.

In addition, the body can use individual sections of DNA in different ways, although its structure remains unchanged throughout its life. These mechanisms are called epigenetic, or supragenetic. As a result, genes work differently from person to person. For example, the use of certain drugs increases the production of certain proteins in the human body that increase addiction.

The external environment also has a significant impact: environment, upbringing, living conditions. So, poor nutrition negatively affects the growth of children, regardless of genes.

Therefore, even people with very similar DNA are not identical. The simplest example is identical twins. Genetically, they are as close as possible, but there is always a difference between them. Both in appearance (shape and features of the face, figure, fingerprints) and in character.

3. Using cloning, you can create an exact copy of yourself

Misconceptions about cloning are associated with the idea that genes determine everything in a person. In popular culture, it is often perceived as creating an identical copy of an object with the same physical and psychological characteristics and even memories.

However, as with identical twins, the clones will not look exactly like the original.

For example, although the first cloned cat CC (from the English carbon copy) was genetically identical to its donor named Rainbow, she had many individual characteristics. So, CC grew more lively and inquisitive, because they played with her more, and also, unlike Rainbow, did not have red spots on her coat.

Therefore, you should not think that cloning is making a complete copy.

4. Genetic analysis accurately predicts future diseases

Sometimes this method is used to predict pathologies that may appear in a person. Some unscrupulous companies claim that genetic tests are highly accurate. However, you need to understand that such an analysis only shows the likelihood, and does not accurately predict future diagnoses.

With a high probability, only diseases that are associated with one gene or chromosome are inherited. For example, Down syndrome or hemophilia. Since only one symptom is enough for the appearance, the chance of getting such a pathology from parents is really high.

However, most hereditary diseases are associated with not one but many genes. These pathologies include, for example, cancer, diabetes, Parkinson's and Alzheimer's. The transmission of a large number of genetic traits is much less likely, therefore, the possibility of their inheritance by children from their parents is lower. That is, a predisposition does not always lead to illness.

Finally, not only S. Heine. DNA is not a verdict for genetics, but the environment, lifestyle and much more affects the appearance of certain diseases.

5. Each gene is responsible for a specific trait

The media love to write that scientists have discovered a connection between some part of DNA and a certain function of the body, disease or character trait. Moreover, most often it seems that one specific gene has been found, which, for example, is responsible for aggression or a tendency to bad habits. But this is not the case.

For example, growth is not determined by just one gene. A variety of DNA elements can be responsible for the trait, which at the same time are associated with several features. For example, the FTO gene is associated with obesity and cancer.

To determine such connections, scientists use a special genome-wide association search method. So the researchers found more than 270 markers showing a predisposition to schizophrenia. There are also known about 100 combinations of genes that are associated with obesity, and about 150-200 - with intelligence.

More genome-wide studies show that there is no direct link between heredity and bad habits. Genes only increase the risk of smoking problems 1.

4., alcohol 1.

3.and drugs 1.

3.. Perhaps this is due to character traits that can lead a person to addictions.

In addition, different studies find different groups of markers. Therefore, it is impossible to link each trait to a specific gene.

6. All mutations are harmful

A mutation is any change in the genome. Evolution would have been impossible without it. It is thanks to the mutation that the inhabitants of different parts of the planet have adapted to the specific conditions of their habitats.

Of course, there are also harmful options. For example, associated with a predisposition to cancer. But changes in the genome also may not significantly affect our life at all. There is an overwhelming majority of them. This is because carriers of harmful mutations die more often without transferring genetic material.

The least useful changes are, but they can be really cool. For example, by possessing the CCR5 -del32 mutation, a person becomes resistant to HIV and other diseases such as cancer and atherosclerosis.

Therefore, you should not think that a mutation always leads to illness or, for example, terrible changes in appearance.