How many have to read on the Internet very sad stories about husbands who blame wives for infidelity because the child does not look like his father, or his mother-in-law, for the same reason suspecting the daughter-in-law of treason to his beloved offspring. But it would be possible to avoid many misunderstandings and to preserve peace and harmony in such families, fall into the hands of these grief-dads and grandmothers an ordinary textbook on genetics.
To the lack of knowledge does not lead to similar family dramas, let's clarify the situation. So, why, in most cases, in most cases, children are like their parents, but it does not exclude cases when a child does not look like his father or does not look like any of his parents at all?
Here is an example from my own family. My mother all my life doubts that she is the child of her parents. Indeed, in addition to the color of the eyes and hair (from the mother) and the propensity to joint diseases (from the father), she does not seem to have inherited anything. Moreover, my grandmother (mother's mother) many years ago added fuel to the fire, saying: "She does not look like us at all, as if she was replaced in the hospital."
Well, guided not only by the need to clarify this topic for readers, but also personal interest, I will try to figure out who the child should be like, if at all, of course, something should someone.
The Truth About the Inheritance of Characteristics
So, first, let us recall the school lessons in biology, where we all were told the simplified scheme of the inheritance mechanism. Genes are responsible for the inheritance of certain traits. Genes are dominant (strong) and recessive (weak). Each individual, whether a cat, a dog, a horse, an insect or a person, inherits a pair of genes, that is, one for each parent. It turns out that the genes of this individual can be either completely dominant, or mixed, and possibly only recessive. It turns out a kind of lottery. There are, of course, certain regularities: the dominant genes are so called, that most often they are manifested in the phenotype (individual characteristics of the individual). But every rule has exceptions.
In humans, the genes responsible for the dark color of the eyes, hair and skin, curly hair, large facial features are considered to be the dominant genes. Accordingly, for light eyes, light and straight hair, pale skin, finesse, the genes are recessive. Hence the pattern:
- dark-haired brown-eyed parents, as a rule, the same children are born;
- the child of the shaten and dazzling blonde is more likely to "suit" go to the father, but can inherit and mum's blondness;
- but for blonde carriers of recessive genes, the appearance of the offspring is hardest to predict, since it can be affected by the dominant genes of grandparents, as well as more distant ancestors.
I repeat that this is only a pattern, a rule that may well have exceptions. For example, a mother with wavy hair, and a curly father, both can have mixed pairs of genes (having one dominant ("curly") and one recessive ("straight-horned") gene), and only a recessive child. As a result, a child with straight hair will be born, which, of course, is amazing, but in no way should cause mutual mistrust of the parents.
Myths about the inheritance of traits
Let's dwell on the frequently occurring on the Internet and media pseudoscientific allegations as to who the first child should look like, as well as the effect on the offspring of the genes of the previous sexual partners of the mother.
Myth 1 . The first child always looks like a dad, and the second one looks like a mother. It is unclear, on the basis of whose personal observations this conclusion has appeared. There are no scientific and statistical data in its favor.
Myth 2 . The theory of telegony - the supposed influence of the first man on all the offspring of a woman. There is also the view that all sexual partners leave a woman with genetic information, which later manifests itself to some extent in her children. This theory appeared in the first half of the XIX century on the basis of the results of the experience of crossing a horse with a zebra, which even Charles Darwin described: this crossing did not give offspring, but the subsequent, single-species crossing, led to the birth of striped foals. However, it is known that at the end of the nineteenth century this experience was at least twice repeated by scientists, and there was never a single offspring with zebra signs. Perhaps the surprising result of Darwin's experience was a consequence not of the phenomenon of telegonics,
Anyway, at all times the birth of the baby was accompanied and accompanied by heated arguments of relatives about who the child is more like. If the child is like his mother, grandmothers and grandfathers on my mother's side rejoice, if the pope, his relatives proudly declare: "And a little something - in our breed!" All this is understandable, because everyone wants to see in the little man his continuation . But do not be upset if the baby was not born like you. All people are different, and nature has managed wisely, creating such diversity. After all, you will agree, it would be boring to raise and educate your exact copy.