Native European color
Part of the world's population is born with fair skin. The homeland of mankind is Africa, the skin color of our ancestors was dark. For a long time, the hypothesis that the fair skin got to the Europeans from Neanderthals remained popular. DNA analysis of Neanderthals showed that in their population there were indeed people with different colors of hair and skin. Modern research refutes the popular hypothesis, arguing that the skin color of Europeans began to change after the extinction of Neanderthals. Gradually, the shade approached modern. Now, discoloration of the skin is explained through physiological processes.
A tall, fair-skinned man who assimilates lactose well is a typical description of a modern European boy. In fact, these European youths are no longer those that were 8,000 years ago. Why do Europeans have light skin in new material from Genotek.
If you are in company with an anthropologist, a geneticist and an evolutionist, and you are bored, ask: “Did the ancestors of modern humans and the Neanderthals cross?” If you believe the research, Neanderthals had an attractive appearance, there were different shades of hair and skin. On the one hand, we have a lot in common with Neanderthals. DNA testing today shows what percentage of the Neanderthal genome is in your own. Variants of genes associated with the development of diseases, such as diabetes and Crohn's disease, were inherited from Neanderthals. However, the common features in the genome could get to us and them from a common ancestor. A mechanism for changing pigmentation is different from that used by modern people.
After moving to Europe, people needed to change their appearance and diet. The modern hypothesis is that the distribution of these signs in the population was motivated by the need for vitamin D. This vitamin can be produced in the skin under the influence of ultraviolet radiation, and can come from the outside with dairy products. Thus, in the course of evolution, 2 solutions were immediately proposed for the problem of vitamin deficiency. The first solution: make the skin susceptible to ultraviolet light. The second solution: to create an enzyme for the efficient production of vitamin from dairy products.
Veronika Musatova, consultant at Genotek Medical Genetic Center: “Vitamin D is necessary for normal bone formation and growth. It regulates the exchange of calcium and phosphorus. With a balanced and nutritious diet and periodic exposure to the sun, there is no cause for concern. If there are signs of hypovitaminosis, loss of appetite, insomnia, convulsions appear, osteoporosis develops and osteomalacia - softening of the bones. ”
If before each new genome of the ancient man was an event, now scientists are working on a full-genome scale with data from several ancient people. Harvard anthropologists have analyzed 83 genomes of the ancient people of Homo sapiens from archaeological sites in Europe dating from 8,000 years BC. Until now. The main objective of the study is to find genes that for some reason have become dominant in the European population over the past 10 thousand years. For comparison, the genomes of modern Europeans from the project “1,000 genomes” were used. The beauty of working with the genome is that it is a sequence of characters - to solve a number of problems, it is enough to determine the genotype in a specific position. A total of 390,000 genomic loci (single positions in the genome) were analyzed.
Harvard anthropologists divided the results into 3 groups depending on the nature of the changes. "Fashion trends" are constantly changing with the population; “Random changes” occurred regardless of external causes, and “fundamental metamorphoses” significantly transformed the population under the influence of natural selection. The genes belonging to the latter group were of most interest to scientists. They are associated with skin pigmentation and nutritional characteristics. In the distant past, the Europeans were black people who did not consume milk. The work of lactase in the human body began after the domestication of livestock and after the migration of the steppe tribes of the Black Sea herders, that is, about 4,300 years ago. The change in diet caused a demand for the development of specific physiological signs.
The work of genes that have changed with the arrival of man in Europe, was associated with metabolism. The strongest selection pressure was observed in the locus, which is associated with the viability of lactase in Europeans. Replacing only one nucleotide affects how this enzyme will be synthesized, and, therefore, the ability to absorb milk sugar - lactose. Also, 2 genes were associated with metabolism: FADS1 and NADSYN1. The FADS1 gene is involved in fatty acid metabolism, and the NADSYN1 gene is associated with the level of vitamin D.
In the new European population, 2 genes that affect skin pigmentation, SLC24A5 and SLC45A2, have spread. The skin is a complex, multifunctional organ of the human body. At the cellular level, skin pigmentation depends on the work of melanocytes - the cells that produce melanin. The SLC45A2 gene helps in the creation of melanin, and the SLC24A5 gene regulates the concentration of calcium in melanocytes. It is curious that inhibitors (substances that inhibit the work of a gene) of the latter are available as commercial injection kits that brighten the skin. Mutations in SLC24A5 and SLC45A2 independently appeared in Europe at about the same time. That is, at that time, as there were two independent white-skinned populations - hunter-gatherers from Sweden and middle Eastern farmers, the main population of Europe differed from them.
Alexander Rakitko, the author and developer of the Genealogy DNA test, which studies the human genetic origin: “We analyzed our database and found out that for the Russian population, besides the SLC24A5 gene variant, which is responsible for bright skin, there are also others. At the same time, according to the database of the project “1,000 Genomes,” there are no other options in the Central European population. In fact, this confirms that the Russian population is different from the population of Europeans, and a comparison of the human genome from Russia with the genome from a worldwide database can show significant differences. ”
Another mutation that has become attached is linked to the HERC2 / OCA2 genes. The work of these genes is associated with the delivery of dark pigment to the iris. The HERC2 gene in this case is a phone call, and the OCA2 gene is the truck that delivers the pigment. If something is wrong on the line or with transport, then the pigment is not delivered, and the eyes remain bright. “By default” the eyes have a dark color, the light shades are due to the fact that the pigment is missing or does not reach the destination.
From a conceptual point of view, this study takes us to a new level of obtaining information about the past. You can compare the data of ancient people and modern and find not only the specific features of populations of the past, but also the general mechanisms of evolution and adaptation in human history. The result of genotyping is information about the genotype in the locus. In the study of evolution, the main interest is focused on the change of genotypes over time.
Modern DNA analysis technologies complement the image of ancient people with features that are impossible to read from the remains of the skeleton. They were able to recreate the contour of the face from the skull before, now the eyes, hair and skin have acquired color. In addition, personal information such as metabolic features, such as lactose intolerance, susceptibility to obesity and resistance to diseases, is disclosed. To build such models, researchers work with the genome. Height, weight, chronic pathologies are complex traits that can be learned about a person from DNA. The dynamics of changes in the genome over time can be traced by comparing the data of ancient and modern people. Analyzing changes, evolutionists and anthropologists estimate the contribution of natural selection and population change over a specific period of time.
These studies show that external features are a means for survival. Now a person is less dependent on the environment, and his phenotypic traits are his own story. And skin pigmentation is not a tool, not a symbol of superiority, not a special right and not special powers. Pigmentation of the skin is simply a phenotypic trait that has changed in the course of evolution in connection with adaptation to certain environmental conditions.
This material was prepared by the Genotek team. We are engaged in genetic research. One of our projects is the Genealogy DNA test, which tells about the origin of a person, his ethnic composition and haplogroup, and also reveals the share of the Neanderthal genome. We are actively researching scientific publications on the topic of human origins and will share with you the results of our work. Read us.
A tall, fair-skinned man who assimilates lactose well is a typical description of a modern European boy. In fact, these European youths are no longer those that were 8,000 years ago. Why do Europeans have light skin in new material from Genotek.
Divide the skin of an ancient man
If you are in company with an anthropologist, a geneticist and an evolutionist, and you are bored, ask: “Did the ancestors of modern humans and the Neanderthals cross?” If you believe the research, Neanderthals had an attractive appearance, there were different shades of hair and skin. On the one hand, we have a lot in common with Neanderthals. DNA testing today shows what percentage of the Neanderthal genome is in your own. Variants of genes associated with the development of diseases, such as diabetes and Crohn's disease, were inherited from Neanderthals. However, the common features in the genome could get to us and them from a common ancestor. A mechanism for changing pigmentation is different from that used by modern people.
Climb out of the skin to move
After moving to Europe, people needed to change their appearance and diet. The modern hypothesis is that the distribution of these signs in the population was motivated by the need for vitamin D. This vitamin can be produced in the skin under the influence of ultraviolet radiation, and can come from the outside with dairy products. Thus, in the course of evolution, 2 solutions were immediately proposed for the problem of vitamin deficiency. The first solution: make the skin susceptible to ultraviolet light. The second solution: to create an enzyme for the efficient production of vitamin from dairy products.
Veronika Musatova, consultant at Genotek Medical Genetic Center: “Vitamin D is necessary for normal bone formation and growth. It regulates the exchange of calcium and phosphorus. With a balanced and nutritious diet and periodic exposure to the sun, there is no cause for concern. If there are signs of hypovitaminosis, loss of appetite, insomnia, convulsions appear, osteoporosis develops and osteomalacia - softening of the bones. ”
83 ancient people
If before each new genome of the ancient man was an event, now scientists are working on a full-genome scale with data from several ancient people. Harvard anthropologists have analyzed 83 genomes of the ancient people of Homo sapiens from archaeological sites in Europe dating from 8,000 years BC. Until now. The main objective of the study is to find genes that for some reason have become dominant in the European population over the past 10 thousand years. For comparison, the genomes of modern Europeans from the project “1,000 genomes” were used. The beauty of working with the genome is that it is a sequence of characters - to solve a number of problems, it is enough to determine the genotype in a specific position. A total of 390,000 genomic loci (single positions in the genome) were analyzed.
The look of the native European
Harvard anthropologists divided the results into 3 groups depending on the nature of the changes. "Fashion trends" are constantly changing with the population; “Random changes” occurred regardless of external causes, and “fundamental metamorphoses” significantly transformed the population under the influence of natural selection. The genes belonging to the latter group were of most interest to scientists. They are associated with skin pigmentation and nutritional characteristics. In the distant past, the Europeans were black people who did not consume milk. The work of lactase in the human body began after the domestication of livestock and after the migration of the steppe tribes of the Black Sea herders, that is, about 4,300 years ago. The change in diet caused a demand for the development of specific physiological signs.
Adaptation to milk
The work of genes that have changed with the arrival of man in Europe, was associated with metabolism. The strongest selection pressure was observed in the locus, which is associated with the viability of lactase in Europeans. Replacing only one nucleotide affects how this enzyme will be synthesized, and, therefore, the ability to absorb milk sugar - lactose. Also, 2 genes were associated with metabolism: FADS1 and NADSYN1. The FADS1 gene is involved in fatty acid metabolism, and the NADSYN1 gene is associated with the level of vitamin D.
Change skin color
In the new European population, 2 genes that affect skin pigmentation, SLC24A5 and SLC45A2, have spread. The skin is a complex, multifunctional organ of the human body. At the cellular level, skin pigmentation depends on the work of melanocytes - the cells that produce melanin. The SLC45A2 gene helps in the creation of melanin, and the SLC24A5 gene regulates the concentration of calcium in melanocytes. It is curious that inhibitors (substances that inhibit the work of a gene) of the latter are available as commercial injection kits that brighten the skin. Mutations in SLC24A5 and SLC45A2 independently appeared in Europe at about the same time. That is, at that time, as there were two independent white-skinned populations - hunter-gatherers from Sweden and middle Eastern farmers, the main population of Europe differed from them.
Alexander Rakitko, the author and developer of the Genealogy DNA test, which studies the human genetic origin: “We analyzed our database and found out that for the Russian population, besides the SLC24A5 gene variant, which is responsible for bright skin, there are also others. At the same time, according to the database of the project “1,000 Genomes,” there are no other options in the Central European population. In fact, this confirms that the Russian population is different from the population of Europeans, and a comparison of the human genome from Russia with the genome from a worldwide database can show significant differences. ”
Eye color logistics
Another mutation that has become attached is linked to the HERC2 / OCA2 genes. The work of these genes is associated with the delivery of dark pigment to the iris. The HERC2 gene in this case is a phone call, and the OCA2 gene is the truck that delivers the pigment. If something is wrong on the line or with transport, then the pigment is not delivered, and the eyes remain bright. “By default” the eyes have a dark color, the light shades are due to the fact that the pigment is missing or does not reach the destination.
Adam, Eve and me
From a conceptual point of view, this study takes us to a new level of obtaining information about the past. You can compare the data of ancient people and modern and find not only the specific features of populations of the past, but also the general mechanisms of evolution and adaptation in human history. The result of genotyping is information about the genotype in the locus. In the study of evolution, the main interest is focused on the change of genotypes over time.
Restore skin color by DNA
Modern DNA analysis technologies complement the image of ancient people with features that are impossible to read from the remains of the skeleton. They were able to recreate the contour of the face from the skull before, now the eyes, hair and skin have acquired color. In addition, personal information such as metabolic features, such as lactose intolerance, susceptibility to obesity and resistance to diseases, is disclosed. To build such models, researchers work with the genome. Height, weight, chronic pathologies are complex traits that can be learned about a person from DNA. The dynamics of changes in the genome over time can be traced by comparing the data of ancient and modern people. Analyzing changes, evolutionists and anthropologists estimate the contribution of natural selection and population change over a specific period of time.
Tabula rasa
These studies show that external features are a means for survival. Now a person is less dependent on the environment, and his phenotypic traits are his own story. And skin pigmentation is not a tool, not a symbol of superiority, not a special right and not special powers. Pigmentation of the skin is simply a phenotypic trait that has changed in the course of evolution in connection with adaptation to certain environmental conditions.
This material was prepared by the Genotek team. We are engaged in genetic research. One of our projects is the Genealogy DNA test, which tells about the origin of a person, his ethnic composition and haplogroup, and also reveals the share of the Neanderthal genome. We are actively researching scientific publications on the topic of human origins and will share with you the results of our work. Read us.