[Eight-month-old sororal twins napping](By Photo by and ©2006 Dustin M. Ramsey (Kralizec!) - My own photographic work., CC BY-SA 2.5, Link)
Today I want to draw your attention to the way people look. The main difference is of course the color of the skin. But the conversation is not about that. We know that the appearance of a person is determined by the genes that it receives as a result of the crossing of genes from its parents. Indeed, it is logical that the appearance is already predetermined in the human genotype at the very beginning and it is impossible to change it. Just a question. Why then the twins look almost always the same or very-very similar, but the children of the pogodki can differ drastically, although there is an apparent similarity.
[Marian and Vivian Brown, identical twins, photographed by Christopher Michel](By Christopher Michel - https://www.flickr.com/photos/cmichel67/14146231281/, CC BY 2.0, Link)
It is rare that parents differently raise their children, but why then the children are so different. If the initial conditions were the same, the genes did not change. Why development goes in different ways. And not only look different in different ways, but also learn differently in behavioral skills. But twins are almost always very similar in appearance and behavior.
My assumption is that age influences development. Twins grow in the same conditions and get everything the same. Like puppies from one bitch. If we consider the weather conditions, children that were born with a difference of one year, then the difference is significant. Really one year so can strongly affect growth and development. Once again, I recall the genes are the same. Perhaps the appearance and behavior are influenced by the conditions of conception. But twins do not look the same. These are children who were born simultaneously, but not twins.
There is an opinion of scientists that people look differently so that we can distinguish people. If animals are able to identify another individual by smell, then the person is more inclined to perceive everything visually. Genes that affect the development of the shape of our face, nose and eye color are more diverse, although limited. As we mix the cards in the deck, so do the genes that affect the development of the face and eyes. But sooner or later a combination may fall out, which has already been encountered before. The facial features have far more variables that affect the appearance than the rest of the body. As a result, we always have distinctive people, except for the twins. Although there are people very similar, and quite in another part of the world, which speaks of the limited genes responsible for development and the general beginning and origin of man.
[Giambattista Della Porta, De humana physiognomonia (Vico Equense [Naples]: Apud Iosephum Cacchium, 1586](By Giambattista della Porta - Porta, Giambattista della: De humana physiognomonia libri IIII. From website of the National Library of Medicine: https://www.nlm.nih.gov/exhibition/historicalanatomies/porta_home.html, Public Domain, Link)
The set of genes responsible for the appearance does not depend on the parents, since it has a certain set for selection, although it is limited by the genotype of the parents. In combination with various growth and development, we get people not similar to each other. And one more confirmation that man is a man-made creature, thought out, and not a set of random transformations ...
Something like this
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