How eye color is transmitted from parents to children. Calculate the color of the eyes of a child.
Eye color is a characteristic determined by pigmentation of the iris. Eye color is a charming and interesting topic that has captured numerous researchers over the centuries, until science helped us better understand the nature of the origin of eye color, and most importantly, how it is inherited.
When it comes to predicting the color of the eyes of a child, one thing is for sure - the baby will be born with blue eyes. Almost always, the eyes of newborns have exactly the blue color, which subsequently darkens as sunlight is exposed to it. By about three to four years old, the eyes of a child usually acquire their permanent, lifelong color, be it blue, green, hazel, amber, gray, dark brown or even dark red .
We hope that future parents will use this article as a kind of help to determine the color of the eyes of their baby. It does not matter whether you will delve into the scientific theory concerning the prediction of eye color in children, these tips are intended to be an excellent basis for determining the color of the eyes of a child for expectant mothers and fathers. Use it as an aid to a reasonable prediction made on the basis of long hours of research.
The iris consists of the anterior - mesodermal , and posterior - ectodermal layers.
The front layer consists of the outer border and stroma. It contains chromatophores containing melanin. The color of the eye depends on the nature of the distribution of pigments in this layer.
The back layer contains many pigmented cells filled with fuscin. Regardless of eye color, the back layer is dark, with the exception of albinos only. In addition, the role played by the vessels and fibers of the iris.
Inheritance of eye color from the point of view of science
The question of eye color and how it is transmitted from parents to offspring has been a topic for many debates among specialists in the field of genetics for many years. There is an established opinion that the color of the eyes of a child is inherited according to the laws of Mendel. According to this law, eye color is inherited in almost the same way as hair color: dark color genes are dominant, i.e. the distinctive features (or phenotypes) encoded by them take precedence over the distinctive features encoded by the lighter-colored genome.
Parents with dark hair will most likely have children with dark hair; the descendants of blond parents will be blond; and a child of parents whose hair color is different will have hair whose color will be somewhere in the middle between the parents. Of course, there are exceptions, but there are also regularities of the processes described by Darwin, Lamarck and Mendel a century ago. There are also rules that describe code and inheritance for most genes.
Some fun eye color facts.one
You probably know that the most common eye color in the whole world is considered brown, but did you know that the rarest eye color is green? In fact, less than two percent of the entire population of the earth has green eyes. If we talk about countries separately, then Turkey has the highest percentage of citizens with green eyes, namely: 20%. There are also a certain number of countries, located mostly in Asia, South America and the Middle East, with residents whose green eyes are almost completely absent.2
Did you know that for the inhabitants of the Caucasus blue eyes are the most characteristic, not counting amber, hazel, gray and green? Also, more than 80% of Icelandic residents have eye color that is either blue or green.3
Not often, but very noticeable phenomenon, called heterochromia, leads to the fact that the eyes of a person have a completely different color. The American actress Mila Kunis, known for the TV shows "The Show of the 70s" and "Family Guy," has one blue eye and the other green eye. In Kate Bosworth, who played in the pictures "Blue Wave" and "Superman Returns", both eyes are blue, but the lower part of the right eye contains large patches of brown color. David Bowie, author of the hits "Ziggy Stardust" and "Labyrinth", is perhaps the most famous celebrity with a non-matching eye color. However, few people know that the difference in the color of Bowie's eyes is the result of an injury he received as a teenager during a game of football, but not heterochromia.
Eye color from grandparents - to our grandchildren is transmitted genetically.
Tables for calculating the color of the eyes of an unborn child
Eye color from grandparents - to our grandchildren is transmitted genetically. During pregnancy, many parents can not wait to find out what eye color their unborn child will have. All answers and tables for calculating eye color - in this article. The good news is for those who want to pass on their own eye color to descendants: it is possible. Recent studies in the field of genetics have discovered new data on the genes that are responsible for eye color (2 genes used to be known for eye color were known, now there are 6 of them). At the same time, all questions regarding the eye color of genetics have no answers for today. However, there is a general theory that, even with the latest research, provides a genetic basis for eye color. And consider it.
So: each person has at least 2 genes that determine eye color: the HERC2 gene is located on the 15th human chromosome , and the GEY gene (also called EYCL 1 ), which is located on the 19th chromosome .
A person has two copies of this gene, one he receives from his mother, one from his father. HERC2 is brown and blue, that is, one person has either 2 brown HERC2 or 2 blue HERC2 or one brown HERC2 and one blue HERC2:
HERC2 gene 2 copies *Brown and Brown
Brown and Blue
Blue and Blue
Human eye colorBrown
Blue or Green
Where does the green blue eyes of the owner of two blue HERC2 come from is explained below. For now, some data from the general theory of genetics: HERC2 brown is dominant, and blue is recessive, so the carrier of one brown and one blue HERC2 eyes will be brown. However, the carrier of one brown and one blue HERC2 with a probability of 50x50 can transfer both brown and blue HERC2 to its children, that is, the dominance of the brown does not affect the transmission of a copy of HERC2 to children.
If a wife has hazel eyes, even if they are "hopelessly" brown - that is, she has 2 copies of hazel HERC2, all children born with such a woman will have brown eyes, even if the man has blue or green eyes, since she will give the children one of its two brown genes. But grandchildren can have eyes of any color.
HERC2 from the mother - hazel (mother, for example, both HERC2 brown)
HERC2 from father - blue (for father, for example, both HERC2 are blue)
HERC2 in a child - one brown and one blue. The color of the eyes of such a child is always brown; at the same time, he can transmit his blue HERC2 to his children (who can also get blue HERC2 from the second parent and then have eyes of either blue or green).
We now turn to the gene GEY
It is green and blue (blue, gray); each person also has it in two copies: one copy is received from the mother, the second from the father. The green gey is the dominant gene, the blue gey is recessive. A person thus has either 2 blue gey genes or 2 green gey genes or one blue and one green gey gene. At the same time, it affects the color of his eyes only if he has HERC2 from both parents - blue (if at least from one of the parents he received brown HERC2, his eyes will always be brown).
If a person has received blue HERC2 from both parents, depending on the gey gene, his eyes may be of the following colors:
GEY gene: 2 copies
- Green and Green
- Green and blue
- blue and blue
Human eye color
The general table for calculating the child's eye color, the brown eye color is marked “K” , the green eye color is marked “З” and the blue eye color is marked “G” :
Using this table, it can be said with a high degree of probability that the child’s eyes will be green, if both parents have green eyes or one of the parents has green eyes and the second one has blue eyes. You can also say for sure that the eyes of the child will be blue, if both parents have blue eyes. If at least one of the parents has brown eyes, their children may have hazel, green or blue eyes.
- two brown-eyed parents have a 75% chance of a child having brown eyes, 18.75% green and 6.25% blue.
- if one of the parents is brown-eyed, and the second is green-eyed, the probability that the child will have brown eyes is 50%, green - 37.5%, blue - 12.5%.
- if one of the parents is brown-eyed, and the second is blue-eyed, the probability that the child will have brown eyes is 50%, blue - 50%, green - 0%.
Thus, if a child's eyes are not the same color as his parents, there are genetic reasons and grounds for this, because "nothing disappears without a trace and nothing is taken from nowhere."
The outer layer of the vessels of the iris, formed from collagen fibers, is distinguished by a dark blue color. If the fibers of the outer ectodermal layer of the iris are characterized by low density and low content of melanin, then it has a blue color. In the iris and in the eye there are no blue or blue pigments at all. Blue is the result of scattering of light in the stroma. The inner layer of the iris, in contrast to the outer, is always saturated with melanin and has a black-brown color. As a result, part of the high-frequency component of the spectrum of light incident on the eye is scattered in the turbid medium of the stroma and is reflected, and the low-frequency component is absorbed by the inner layer of the iris. The lower the density of the stroma, the richer the blue color. Many babies have this color in the first months of life.
Unlike blue eyes, in this case the density of stromal collagen fibers is higher. Since they have a whitish or grayish tint, the color will no longer be blue, but blue. The greater the density of the fibers, the brighter the color. Blue eye color is the result of a mutation in the HERC2 gene, due to which the carriers of such a gene have reduced melanin production in the iris of the eye. This mutation arose about 6-10 thousand years ago. Blue and blue eyes are most common in Europe, especially in the Baltic States and Northern Europe. In Estonia, up to 99% of the population have this eye color, in Germany - 75%. In Denmark in the 1970s, only 8% had dark eye color, whereas now, as a result of migration, this figure has increased to 11%. According to a 2002 study, among the Europoid population of the United States born in 1936-1951, carriers of blue and blue eyes make up 33.8%, while among those born in 1899-1905 this figure is 54.7%. According to 2006 data, this figure for modern white Americans has dropped to 22.3%. Blue and blue eyes are found in the Middle East, for example, in Afghanistan, Lebanon, Iran. They are also common among Ashkenazi Jews, for example, among Ukrainian Jews, the percentage of carriers of these flowers is 53.7%.
Gray eye (steel shade)
The definition of gray and blue eyes is similar, except that the density of the fibers of the outer layer is even higher and their shade is closer to gray. If the density is not so great, then the color will be gray-blue. The presence of melanin or other substances gives a small yellow or brownish impurity. The gray color is presumably due to the scattering of Mie by the fibers of the outer layer, which, unlike Rayleigh, is less dependent on the wavelength; as a result, the spectrum of light reflected from the iris is closer to the source spectrum than in the case of blue or blue eyes. Gray eye color is most common in Eastern and Northern Europe. In Russian, this color, according to the data of 1909, reached 50%. It is also found in Iran, Afghanistan, Pakistan and some regions of North-West Africa.
Green eye color is determined by a small amount of melanin. In the outer layer of the iris is distributed yellow or light brown pigment lipofuscin. In total, the resulting blue or blue color from the stroma results in green. The color of the iris is usually uneven and there are a lot of different shades. In its formation, it is possible that the gene of red hair plays a role. Pure green eyes are extremely rare. Its carriers are found in northern and central Europe, less often in southern Europe. According to studies of the adult population of Iceland and Holland, green eyes are more common in women than in men.
Amber eyes have a monotonous light yellow-brown color. Sometimes they are characterized by golden green or
Swamp Swamp eye color is a mixed color. Depending on the lighting, it may have a golden, brown-green, brown tint. In the outer layer of the iris, the melanin content is quite moderate, so the swamp color is obtained as a combination of brown, which is given by melanocytes, and blue or blue. Yellow pigments may also be present. Unlike amber, in this case the coloring is not monotonous, but rather heterogeneous. In some cases, the eye color may seem not so much marsh (brown-green) as light brown with a yellow-green shade, so in the English tradition it is called walnut (eng. Hazel), and in Polish - beer (eng. Piwny).
In this case, the outer layer of the iris contains a lot of melanin. Therefore, it absorbs both high-frequency and low-frequency light, and the reflected light adds up to brown. Brown is the most common eye color in the world. It is ubiquitous in Asia, Oceania, Africa, South America, as well as in Southern Europe.
The structure of the black iris is similar to brown, but the concentration of melanin in it is so great that the light falling on it is almost completely absorbed. In addition to the black iris, the color of the eyeball may be yellowish or grayish. This type is distributed primarily among the Negroid race in South, Southeast and East Asia. In these regions, newborns are immediately born with a rich melanin iris.
How your future child will look like (Infographics)
Who your children will look like - it's incredibly curious to find out, isn't it? Science today works wonders and can easily predict what family traits will be given to a future baby.
The site AdMe.ru analyzed genetic schemes and made approximate portraits of children from parents of different types of appearance.