The world’s biomedical history has recorded strange and bizarre phenomena and this event from 7,000 years ago is a very typical example.
Specifically, this is the period that witnessed a terrible collapse in the number of genes of … men, lasting up to 2,000 years. According to a new study published in the journal Nature Communication, the Y chromosome has been missing for generations. At one point, the number of men in the Old World was reduced to a ratio of 1:17 to women.
Old World: The name of the Earth was known to Europeans before Christopher Columbus discovered America in 1492. The Old World includes: Europe, Asia and Africa (also known as the African continent- Eurasia) and surrounding islands.
After about 2000 years of continuous decline, there is only one man left for every 17 women.
About 7,000 years ago, man almost died out.
In the past, scholars have suggested that this may have to do with our ancestors’ discovery and settlement of new lands. They call it the “founding effect,” when small groups of individuals are constantly moving to discover new lands.
However, a new study published in the scientific journal Nature uncovers a much more devastating truth. Men at that time killed each other.
The number of men in Europe, Asia, Africa and the Middle East dropped dramatically due to this phenomenon about 5000 to 7000 years ago. The father’s Y chromosome will be passed on to his sons, which is why nearly entire families have been wiped out on a large scale. At one point, the world’s population was estimated at between 5 and 20 million, with more than 9.5 million men killed.
But why?
In 2015, research in the UK published in the journal Nature first mentioned this phenomenon. They suggest that a large number of males disappeared at a time when people switched from hunter-gatherer lifestyles to farming and farming. It is hypothesized that at this time, some men became dominant in power, and they imposed and controlled the fertility of their inhabitants.
This does not necessarily mean that the total number of men has decreased. The problem is that conceiving and giving birth to a boy is hindered, causing the Y chromosome to gradually shrink. As a result, the genome also collapsed.
The Stanford team says the reason is “competition between blood groups”. The team created 18 computer simulations that included different scenarios for the decline in the number of males, including factors such as Y-chromosome mutations, competition between men and women. ethnicity and mortality.
The results showed that war between patriarchal clans caused many men to die before they could have sex to have children, thereby reducing chromosome diversity. And since the patriarchal clans have the same Y chromosome, if one clan destroys another, it also means that the Y chromosome is unlikely to be passed on to the next generation.
Wars between patriarchal clans resulted in the death of many men.
And yet, after those wars, the number of women is often higher than that of men. Marcus Feldman, study author at Stanford University, said: “In the same patriarchal clan, women can come from anywhere. They can come from another clan that has lost the war or be women who have lived in the area before.”
Essentially, the winning clans will exterminate the opponent’s men to ensure continued dominance and eliminate potential competition. They will then capture the surviving women. “If you look at the history of the colonies, you will see that people used to kill all the men and keep the women for themselves.”
Chris Tyler Smith – evolutionary geneticist at the Sanger Institute (UK) – said: “Researchers at Stanford University conducted careful computer simulations before coming to a conclusion. The hypothesis is that, Ancient warfare is a very plausible cause of the Y-chromosome cork, especially in the Neolithic.”
Humans still lived in small farming clans from 5,000 to 7,000 years ago. Then they moved on to larger social groups and built big cities. During this period, the male population gradually recovered. “It’s the conversion of farming that uses stone tools to metal tools,” says Tyler-Smith.
“Our results are supported by archaeological discoveries and anthropological theories,” said the Stanford team.
Evidence of Neolithic wars can be found in fossil skeletons throughout Europe, including Britain. Many of the skeletons showed signs of being attacked by bows, maces and stone axes – weapons of the people of the time.
Marta Mirazón Lahr, an anthropologist at the University of Cambridge (UK), said: “The fossils show that these people – who lived by hunting and gathering – were massacred in a deliberate attack. of raiders from other regions”.
The most reasonable hypothesis available
Their conclusions have been agreed by quite a few historical experts. However, the team from Stanford University does not think so. Recently, they turned the issue around with a different approach.
Using mathematical modeling and computer simulations, they traced back the tribes that had waged many wars over resources, and tracked NTS Y across the entire population.
For those who don’t know, ancient clans were often patriarchal, meaning that these tribes already had a low Y-chromosome distribution because the entire lineage was dependent on a few male rulers. And through Stanford University research, those wars actually cause the distribution of chromosomes to drop even lower.
In biology, this is known as a “bottleneck” phenomenon – which occurs when the biodiversity of a population decreases.
War causes death – whether men, women or children. But because the proportion of men in the army has always been in the majority, the death rate for men is also more skewed. Therefore, after wars, the number of women is often higher than that of men.
The experts behind the research
Moreover, the wars of the past were extremely barbaric in nature. The winners often make the losers extinct, and that can be the reason for the “bottleneck” phenomenon.
However, this conclusion still has many loopholes and cannot be confirmed. Even experts from Stanford say this is a hypothesis, nothing more.
Only that, historical data only confirms that a strange phenomenon happened to men, but does not show why. And determining the cause is still downgrading.
