As soon as the baby comes to this world, grandparents, friends and acquaintances, aunts and uncles and, of course, the newly made parents themselves ask themselves who the baby looks like. Whose nose is it, mouth, cheeks. And one of the main questions is: "What eye color will the child have?" Can blue-eyed parents have a brown-eyed girl? Or does a dark-eyed couple have a boy with blue eyes? Let's figure it out!
What determines eye color in children? There can be no definite answer here, because even though 90% is decided by genetics, the remaining 10% still depends on the case.
The color of human eyes is determined by the amount of pigment called "melanin" in the iris . The minimum amount of melanin means blue eye color , the maximum amount is brown. The remaining colors and shades are between these two points of the spectrum. The amount of pigment is determined genetically.
All newborns have either dark brown or gray-blue eyes. Then, depending on the speed and amount of melanin produced by the body, the color of the eyes will change. Finally, you can determine what eye color your child will be when he reaches the age of three. Until this age, it can change, but for most children everything is clear already from the age of six months to a year. There are exceptions to the rule: there are people whose eye color changes throughout life.
The misconception is that if both parents are brown-eyed, the child should also have this eye color. To their surprise, a blue-eyed child may also be born. How many families broke up due to such cases when people had no idea what genetics is. Of course, suspicion fell on the woman. Meanwhile, everything is quite simple. Let's look at the simplest example from a modern school textbook on biology.
What color of eyes will the child have? Guessing in advance will not work. Each person has two variants of the same gene: maternal and paternal. Two versions of the gene are called alleles. One of them will be dominant, the other will be recessive. So, brown eye color is dominant. But a child can also receive a recessive allele of one of the parents.
Denote brown color of the eyes with the letter "K", and blue, which is recessive, a small "g". For the color of the eyes in the human body, a combination of two alleles is responsible - one from each parent. Thus, the brown-eyed person will either have a combination of "QC" or "Kg." A blue-eyed child, in turn, can only have "yy."
The child may have blue eyes, if both dark-eyed parents have an incomplete dominance of brown color, that is, both have the Kg allele. In other words, if the grandparents of the child have blue eyes, their grandson may well be blue-eyed!
Mom “Kg” + father “Kg” = KK (brown-eyed baby) or Kg (brown-eyed baby) or gg (blue-eyed).
Today, there are even peculiar calculators to determine what color the eyes of the child will be. Of course, our explanation is very schematic and does not reflect the entire complexity of genetic processes. Still, the conception and development of a child is a great mystery, and our mind is not always able to recognize it. What color of eyes will the child have - is it so important? It is much more important that he be healthy and live a happy life, is not it?