Reasons why men in the world were mass-dead long ago are revealed by gene research

There are times when the majority of men living in Asia, Europe and Africa died between about 5000 years ago and about 7000 years ago, and we know that there were only 1 male for 17 women I will. Although I was bothering many researchers with the question "Why did it fall into such a situation?", The reasons for Marx Feldmann et al., Professor of genetics at Stanford University, etc. Has been revealed.

Cultural hitchhiking and competition between patrilineal kin groups explain the post-Neolithic Y-chromosome bottleneck | Nature Communications
https://www.nature.com/articles/s41467-018-04375-6

Why Do Genes Suggest Most Men Died Off 7,000 Years Ago?
https://www.livescience.com/62754-warring-clans-caused-population-bottleneck.html

This man is very few "Y chromosomeThe fact that the bottleneck of 'Established' occurred in Estonia's 2015Study of University of TartuMany researchers have been investigating the reasons since they were shown.

The reason that this phenomenon is expressed as "bottleneck of Y chromosome" comes from the characteristics of Y chromosome possessed by men. There are 23 pairs of chromosomes in human somatic cells, and the gender is determined by the combination of the 23rd pair. If you are a woman twoX chromosomeIt also knows that if you have one X and one Y chromosome you will become male. In addition, children inherit chromosomes one by one from their parents, but for Y chromosomes they will only receive from men, and if they do not mutate, their father, father, son and Y chromosome are inherited from grandfather Even the Y chromosome will rarely change. For this reason, this phenomenon is called "Y chromosome bottleneck" because when the male is mass death, the Y chromosome for the dead man disappears.

Two hypotheses are cited as reasons for the occurrence of "Y chromosome bottleneck" in the research by Tartu University, one being "due to ecological factors and climatic factors", the other being " Men have social power, and that mass death has occurred because the children made too many children? "


However, Mr. Feldman pointed out that these two hypotheses can not explain because the ratio of 1: 17 is too extreme. Therefore, the research team set up 18 kinds of hypotheses such as "Mutation of Y chromosome", "War between different races", "Natural death", etc. in order to investigate the situation occurring in the group at that time, I did a simulation.

Through these simulations, the most dominant hypothesis is that the war is being carried out among the groups, and the men of the losing group are all killed. If all the men in one group of men are killed, it will lead to the loss of the Y chromosome by the number of people killed and it will also be the reason for the "Y chromosome bottleneck".

Also, there was no similar bottleneck in women at that timeMitochondrial DNAIt is clear from the analysis of. About this fact, Mr. Feldman said that if you trace to the history of colonized areas in the past, you can explain, "All the men in the group are killed, but women tend to survive by moving to the victorious group It is in. "


Chris Tyler Smith, an evolutionary geneticist at the Sanger Institute in the United Kingdom said, "With regard to the bottleneck of the Y chromosome, studies at the University of Tartu failed to arrive at a reasonable answer, but indicated by a study at Stanford University The hypothesis that the bottleneck is due to war is becoming rational, "he believes that the hypothesis presented by Mr. Feldman's team is powerful.

Mr. Feldman said, "Since the era of Y chromosome bottlenecks, similar disputes have been reduced due to the fact that human beings have formed a big society like the city and the diversity of the Y chromosome is reviving." I said.