The study by scientists from the Fresh Pond Institute in Cambridge, Massachusetts, USA, turned out to be rich in results. The researchers tried to find an answer to the question that haunts many - why more boys are born all over the world than girls (proportion 51 to 49). The conclusions of a group of employees of the institute led by Stephen Orzak turned out to be somewhat unexpected.

First, scientists have found that, contrary to popular belief, the number of embryos of boys and girls at conception is equal. Secondly, another widely held, but as it turns out now, erroneous belief has been refuted, which says that the mortality rate among male embryos is higher than among female ones. It is precisely because of his fallacy that more boys are born than girls.

American scientists came to such conclusions after analyzing a large database of American children who were conceived in 1995-2004. Scientists wanted to determine the ratio between the sexes at the time of conception and at the time of birth.

Stephen Orzak and colleagues analyzed the data at different stages of pregnancy and found that boys do not have any advantage at conception and that during pregnancy they die not more, as previously thought, but less. The ratio between embryos of different sexes differs by different terms pregnancy. There are even two periods: the first week and the interval between 28 and 35 weeks of pregnancy, when the mortality rate among male embryos is indeed higher than among female ones. However, in general, by the time of birth, the number of male fetuses is slightly, but still consistently higher than the number of female embryos.

The results of the study, which could force a change in a number of important principles of demography, can be found in the authoritative journal Proceedings of the National Academy of Sciences (PNAS).

Not all of their colleagues agree with the conclusions of American scientists. Fiona Matthews from the British University of Exeter devoted a lot of time and energy to the issue of the ratio between the sexes at the stage of pregnancy and childbirth. World statistics states that on average, 105-106 boys are born for every 100 girls. In her opinion, there is some relationship between the sex of the embryo and what the mother ate before conception. Fiona Matthews analyzed data from 740 British women she asked about their diet before conception. It turned out that those who ate more high-calorie foods were slightly more likely to have sons than daughters.

Fiona Matthews explained this finding by saying that male embryos develop faster and require more calories to develop. Fiona is also supported by supporters of the theory, which claims that more girls are born in times of famine. This was clearly seen in 1959-61 in China, when there was a great famine.

The question remains intriguing to scholars as to why the gender balance persists. men produce great amount sperm, while women have a limited number of eggs. As far as evolution is concerned, main question Why can't humanity make do with fewer men and women? large quantity women?

The internationally accepted answer to this question was given by Ronald Fisher, a well-known evolutionary biologist who worked in the first half of the 20th century. According to Fisher's principle, sex ratio differences will tend to decrease over time due to the reproductive advantage automatically gained by the minority sex.

Suppose that, for example, the number of newborn boys would be much less than the number of newborn girls. If this were true, then newborn boys in the future would have higher prospects for reproduction than newborn girls, and thus the number of offspring would be greater. Parents who are genetically more inclined to give birth to boys will have more grandchildren, so their gene responsible for "producing" men will spread more and more. Gradually, the population will achieve gender balance.

MOSCOW, August 21 - RIA Novosti, Alfiya Enikeeva. There are many recommendations among the people for those who want to conceive a boy. But they all don't work. It was only by using statistical methods on large amounts of data that scientists were able to uncover hidden factors that affect the sex ratio among newborns. How high incomes of parents and regular sex are connected with this - in the material of RIA Novosti.

crocodile children

When a female American alligator (Alligator mississippiensis) is looking for a place to lay her eggs, she actually determines the sex of her offspring. If the nest is more than 33 degrees Celsius, only boys will hatch from the eggs; at temperatures below thirty, girls will appear.

The sex of alligators, like many species of crocodiles, is determined by the thermosensitive TRPV4 protein contained in the gonads (gonads) of embryos. At high temperature environment it opens access to cells to calcium ions. This activates the genes that ensure the development of the male type - the sections of DNA encoding the anti-Mullerian hormone and the Sox9 gene. Some biologists believe that the regulation of the sex of the offspring allows alligators and crocodiles to maintain an optimal ratio for the survival of the species, when there is one male for ten females.

In all countries of the world, more boys are born than girls. There is evidence that Kazakhstan and Nauru are an exception, there are more female babies (93 to 100), but this does not change the overall picture - a person as a species is trying to reproduce more males.

At the same time, given the poor survival rate of boys during embryonic development (according to various estimates, among miscarriages and stillbirths - up to 70 percent of male fetuses), most experts agree that during fertilization, boys are obtained almost twice as often.

On the other hand, an international group of scientists led by Cambridge geneticist Stephen Orzak recently showed that during artificial insemination, boys and girls are conceived equally, and female embryos die just as often (if not more often) during intrauterine development. Boys die in the first weeks of pregnancy and at 28-35 weeks, for girls the second trimester of pregnancy is more often fatal. Orzak suggests that these results can be transferred to natural fertilization, which refutes the theory of the endurance of female embryos.

© CC BY 4.0 / United Nations Population Division. World Population Prospects: 2017 Revision. The World Bank

© CC BY 4.0 / United Nations Population Division. World Population Prospects: 2017 Revision. The World Bank

Abstinence + stress = girl

When I was in position, my husband could not calm down. Tried to determine who I will be born. But for some reason I was calm, because I felt that I would have a daughter. And today they can tell you the secrets of genetics.

Girls or boys: who is more in maternity hospitals

I noticed that people are used to believing in something unusual, but not in science. Instead of reading science news or a smart book, they open horoscopes every day.

With pregnancy, the sex of the child will also take a lot, but they will not help future parents. I strongly recommend paying attention to medicine, hard facts. For example: more boys are born than girls. I don't agree with these statistics. If we take the data of a single city (how many babies were born in a month), such statistics will fail. Because every month there are new data. The girls are in the lead, then the boys.

We have more girls. See for yourself, because there are more single girls than men.

What will happen next

The world-famous biologist Ronald Fisher created his theory back in the twentieth century. He argued that gender equality would come in the 21st century. That is, the number of girls and boys in maternity hospitals will be the same.

A few more facts about babies in the tummy:

• Male and female embryos look the same. Only after 12 weeks they begin to develop.
• The body will use more energy to create a girl.
• The child reacts to his mother's voice while still in the womb, the sounds are heard through amniotic fluid. The voice of outsiders is not always audible to the embryo.
• It is not always possible to see the face of a child on an ultrasound.

Boys and girls are the "flowers" of life

Determining the gender of the unborn child, coming up with a name, buying clothes and equipping the nursery - this is an incomplete list of things for a young family. I don't understand why you're in such a hurry. You need to enjoy this period.

If the question of gender worries you, I will tell you a little secret. Look in your refrigerator. If you eat more foods that contain calcium, magnesium, zinc, there is a high probability that you will have a son.

In Russia, the opinion has taken root that fewer boys are born than girls. Scientists explain this by the fact that male embryos have a lower survival rate than female ones. However, for a complete answer, who is born more boys or girls, it is better to turn to statistics. If we take the country as a whole, then there are more male embryos than female ones (105 versus 100). Then why do brides complain all the time about the lack of grooms?

How many children are born in Russia per year

Fertility is an important indicator of any country. If it is low, then it becomes a threat to territorial integrity. Low mortality and high birth rates improve the economy and serve as a guarantor for the preservation of the nation. This helps to track the birth rate statistics for boys and girls in Russia. Let's take an example depending on the period of government different people, at (in percent):

• Stalin - 2.7;
• Khrushchev - 3.1;
• Brezhnev - 1.7, at the end of the reign - 1.4;
• Gorbachev - 1.2;
• Yeltsin - 0.6;
• Putin - 0.9.

The birth rate directly depends on the well-being of citizens. According to statistics, it can be seen that the peak occurred during the years of Khrushchev's rule, and then it began to fall sharply, and only under Putin began to grow again. The latest value dates back to 2010. However, already in 2015, almost 200 thousand more children were born, and this figure remains.

To determine who is more born, you need to collect data from all regions. About a hundred more boys are born each year than girls. However, their number is equalized by the middle age, and more women remain by the advanced age.

But they also take into account the statistics of children with disabilities. Almost half are born with mental disorders, physical defects. This is mainly due to parental stress, heredity, and ecology. Many of these children do not reach childbearing age or are unable to have offspring.

How many women and men in Russia

If we consider how many more women there are than men in Russia, then in 2018 this ratio was 1156 per 1000. If we take the general figures, then 78.7 million to 68.1 million. According to statistics, more boys are born, but they only prevail up to the age of 34. During this period, there are 960 women for every 1,000 men.

Then the indicators begin to change places. For every 1,000 men aged 35 to 40, there are already 1,027 women. The biggest difference with the predominance of ladies is the group of 70-year-olds. Only in 2017, equality was achieved in the number of women per man (1000:1000).

However, despite the fact that more boys are born, their ratio remains consistently less than 10 percent. According to experts, the birth rate is still low and one of the reasons is that fewer women giving birth to children. For some, one child is enough, other families are not in a hurry to have children at all until they get on their feet financially.

The decline in the male population also depends on other factors. There are more miscarriages among male embryos. Those children who are born, often with congenital diseases, after 30 years are susceptible to bad habits. Suicide, traffic accidents, crimes, poisonings, diseases also lead to an increase in male mortality.

It is interesting that in large cities the number of single women is always greater than that of men. But in Moscow and St. Petersburg the situation is gradually improving. The most harmonious picture is in the Far East. There are more men than women in the Yamal-Nenets and Chukotka districts, Norilsk, Novy Urengoy.

The problem of sex ratio in the world or in a single country has been of interest to human society for many centuries. At present, on this topic, a huge amount of material has been accumulated on the sex ratio in society, both at the birth of children, and separately for each age group. These materials are quite contradictory and contain many inexplicable facts.

Who more - boys or girls are born?

What do scientists say about this? Based on statistical data, they answer that in the world, always and in all countries, regardless of race, 104-107 boys are born per 100 girls on average. Stress, natural disasters, wars - all these factors, confirmed by statistics, increase the percentage of born boys. It has also been established that males begin to predominate in the population when its numbers decrease. This applies to the plant world and populations of marine organisms.

When asked who they want to have more in the family - boys or girls, in India, China, Vietnam, Serbia, Georgia and many others, they will answer you that, of course, boys. For this reason, about 160 million embryos with female sexual characteristics die every year in the world. Women in these countries decide to have an abortion when they find out that they are going to have a girl. It got to the point that, for example, in China, 120 boys are born for every 100 girls. Among the developed countries where the male population predominates, we note such as Australia and the United States.

The last population census for 2010 gives us the answer to the question - who is more, men or women in Russia. Here are some sample data:

• population Russian Federation- 142,856,536 people;
• the female population is (in general) - 53.8%;
• among infants under 1 year old - 48.7%;
• girls under the age of 20 - 49.2%;
• women 21 - 30 years old - 50.1%;
• women 31 - 40 years old - 51%;
• women 41 - 50 years old - 54.3%;
• women 51 - 60 years old - 57.6%;
• women 61 - 70 years old - 64.9%;
• women 71 - 80 years old - 72.4%;
• women 81 - 90 years old - 82%;
• women 91 - 99 years old - 84.5%.

Comparing age groups, it becomes clear who is becoming more in Russia, men or women. It is quite clearly seen here that after the turn of 50 years, the predominance of the female population over the male in our country becomes not only dominant, but stunningly overwhelming.

Now we will try to answer the question - why there are more women than men. The main reason is their longer life expectancy compared to men.

Scientists note 7 main reasons that positively affect the duration of female existence:

1. Genetic (biological) causes.
2. Different actions of female and male sex hormones.
3. A woman cares more about her own health.
4. Caution in women is several orders of magnitude higher than in men.
5. Women are more emotional.
6. Women try to shift decision-making to their men.
7. Women have fewer bad habits.

After analyzing all of the above, we can conclude that for the existence of such a biological species as a person, we see that mother nature herself sacrifices males. A shorter male life allows for a faster turnover of males for the benefit of the whole species. It is appropriate here to recall the slogan of Urlanis, a well-known demographer, that has already become boring to everyone: “Take care of men!”.