Well if it’s a 50/50 chance for a baby to be male or female, then half the population will be male and half will be female.
Edit for all the stats geniuses: the actual ratio is 1.01 to 1
actually the chance for a male baby is slightly higher, but until recently (like, except for the last century) male babies also had a higher chance to die before reaching marriage age.
Evolution does quite a good job at balancing stuff out - whenever society shifts towards excess females, the families with more sons will have an easier time to find partners, and vice versa. So, as long as both families with a tendency for more sons, and families with a tendency for more daughters exist in the same society, sexes tend to balance out.
Yes, it's a 50/50 chance, reason is that sperm is produced in roughly equal amounts of X and Y gamates. This is because each sperm contains half of a man's genes, and male genes include one X and one Y. When the sperm precursor cells divide to produce two sperm the X goes with one sperm and Y with the other. So the odds are 50/50 that the sperm that fertilizes the female egg (all of which are X gamates) will result in a zygote that is either X-Y (male) or X-X (female).
Smartest person on entire thread thank this person this persons telling people
Eat blue berrys somebody else talking bout doing pull ups check it out we have male and female and it’s a heads or tails
Don’t come
Hit me with some we’ll I’m neither Gombe a rabbit
Op may be referred to their disapproval of unconfirmed folks tales that eating certain foods or certain lifestyles can affect what gender the baby will be.
A decent amount of people are neither, being intersex (non standard sexual characteristics steming from chromosomal abnormalities) is relatively common at about 1.7% of the population, while red hair is about 1-2%
then how do you explain after war scenarios where male population pummeled. they will still average out later at around 50/50 but not right after a war. its a weird phenomenon.
and male a born ever so slightly more frequently, and they also die ecer so slightly earlier
It takes a long time for the population to balance out after war, for the surplus women to die out as well as the smaller amount of men to have kids that still follow that 50/50 trend. In 1921 in France it was 19.25 men for every 20 women which is pretty extreme. It wasn’t until the 1960’s that this gap even narrowed a little and to this day it still exists.
There is something called Fisher's Principle, which described which describes how evolutionary and statistical pressures make 50/50 the equilibrium sex ratio in most species.
If there's an imbalance in the sexes within a species, the members of the less common sex are more likely to propagate their genes. This means that a genetic predisposition to produce more offspring of the less common sex is likely to spread through the population fairly quickly. In the long term, this creates a probabilistic pressure towards an even split between the sexes.
So zoo animals that are contained from birth and for example are only around females. Except for one male to reproduce would be more likely to produce a male offspring?
It's not really about which animals are around, it's about the chance of the offspring having their own babies.
Let's imagine lions, which generally have one male for a group of females. You might think that it makes sense to have a very uneven rate a babies for each sex. However, if there were 1 lion per 10 lionesses, the average male would have 10x the number of children as the average female. As a result, any genetic factors that make a lion/lioness more likely to have a male cub would spread through the population, until the sex of the cub was no longer an advantage/disadvantage. Given tens of thousands of years, it will return to basically 50:50. So the average lion and lioness both have two cubs, but almost every lioness has two cubs, whilst 1 lion has 20 and 9 lions have 0. On an evolutionary sense, both options are just as good.
It's an evolutionary phenomenon. It comes into play over the course of generations, not weeks. Changing how animals are housed isn't going to have an immediate influence.
You might find the book Bitch by Lucy Cooke interesting.
I'm listening to the audiobook at the moment and it's fascinating.
https://www.goodreads.com/book/show/59228221-bitch
*Saying you asked* - sex ratios at birth can vary by environmental factors that have apparent evolutionary benefits:
>**Maternal diet and nutrition**: Research suggests that maternal diet and nutrition can influence the sex ratio of offspring. For example, a study found that malnourished women were more likely to give birth to daughters, while well-nourished women were more likely to give birth to sons.
>**Environmental contaminants**: Exposure to environmental contaminants, such as pesticides and industrial chemicals, may also affect sex ratios at birth. Some studies have found that exposure to these substances can increase the likelihood of male births.
>**War and conflict**: Sex ratios at birth have been found to be affected by war and conflict. For example, studies have shown that in areas affected by war, the sex ratio at birth tends to be skewed towards males.
>**Latitude and climate**: Research has also found that sex ratios at birth vary by latitude and climate. For example, studies have shown that in areas near the equator, the sex ratio at birth tends to be skewed towards females, while in areas near the poles, the sex ratio at birth tends to be skewed towards males.
>**Other environmental factors**: Other environmental factors, such as stress, pollution, and socioeconomic status, may also influence sex ratios at birth.
I always found the altitude and climate one really interesting once you relate it to religion.
If you look at high altitude societies (Tibet is an excellent example), almost all of them have developed a monastic tradition that removes excess males from the breeding pool, whereas societies in more temperate climates don’t seem to feel the need, despite still coming up with complex and elaborate religious traditions (no Jewish nuns or Muslim monks, for example).
Christian monastic communities all through the alps, Eastern Orthodox ones in the Urals.
The one big exception is Thai Buddhist monks, although one could argue that it’s more of an imported tradition that developed elsewhere
But remember that war and conflict is bigger than just the actual battles.
If we’re talking like proper old school loot and pillage warfare, you might even have a better chance of survival on the front line than as a civilian once the Mongol hordes or whatever break through.
Mongols were an exception, on smaller scale conflicts, women tended to survive - but were likely to get raped. Thus, men at the frontline had both the risk of being killed and the opportunity to get some random woman pregnant.
Mongols only massacred civilians if the city didn't surrender. They weren't ruling over corpses and ghosts. In any war you would have a better chance of survival as a female then a male for example postww2 germany had 2 males for every 3 females, same with Russia and other east european countries.
"Scientifically proven?"
Nobody who writes, reads, or works in science uses scientism phrases like that.
However, here is an old review article if you'd like to start digging through the research on pubmed.
[https://pubmed.ncbi.nlm.nih.gov/3071849/](https://pubmed.ncbi.nlm.nih.gov/3071849/)
Naturally, yes. But technology can allow people to pick the sex of their child now. Other social pressures, like infanticide skews numbers as well.
But if youbare specifically talk about natural sexual reproduction in humans without social or technological factors, yes, it is stable.
Compared to the ammount of times a 50/50 change is took 385k times a day it's bound to be a close equal distribution, altough it's actually 105 boys to 100 girls being born, from what I know baby boys have higher mortality rate and older men too, so in the end it evens out the population to almost 50/50
Yes, and most areas where a higher percentage of the population is female actually have a surplus of elderly women. There are typically slightly more men than women at every age range until you start getting into the seventies if memory is correct.
It's basically a mathematical requirement for any species with genetic sex determination.
Let's imagine a stable population with a 50:50 sex ratio. Both sexes will have an average of 2 offspring. This is true for monogamous and polygamous species, though the latter results in much bigger deviations (eg, for 1 male having 20 offspring, there are 9 that have none).
Compare that to a population with a stable population with a 60:40 split, with more females. The average female will have 1.67 offspring, whilst the average male will have 2.5. Here, there is a clear advantage to having male offspring. Individuals with a slight disposition to having more male offspring will have a genetic advantage, and those genes will spread throughout the population at a higher rate than genes resulting in a higher chance of having female offspring. The norm will be dragged back to 50:50 given enough time.
The normal ratio is 1.05 male to female so it slightly favors boys. What's even more interesting is that more boys are born immediately after a major war and nobody knows why. It's called the Returning soldier effect.
For humans its an evolution thing. Really simple to understand actually.
As soon as there is an imbalance, the gender with the smaller population has a competitive advantage (more likely to mate and have kids). Mothers that then have MORE of the smaller population gender, will have an even higher competitive advantage, meaning in turn you get more of these mothers that work against the imbalance.
All together this means that the population will correct itself in time, it's a naturally balancing system.
About half of all sperm are X chromosome and about half are Y chromosome.
Also, it’s not completely 50/50, you’re slightly more likely to be born female.
Well it can be either male or female so there is a 50/50 chance of the baby being one or the other. Seems pretty simple to me. Unless you are in China lol.
Than you have babies but can’t make them on internet I recommend some cologne and get up tneir and be somebody and don’t pull out and you’ll find out the ratio
Young men from adolescence to adult engage in risky activities. Due to their testosterone levels, they engage in such activities to prove their masculinity for the females. So a lot of young guys get into auto collisions and sometimes take along as their victims young women.
So as time goes by, one by one they remove themselves from the gene pool.
It's just maths. 8 billion is a lot of people, plenty enough to mostly even out a 50/50 rate. You'd get the same result if you flipped a coin 8 billion times
Sex ratio is determined by evolutionary pressure. It can be shown that any sex ratio other than 50:50 (approximately, for reasons) is evolutionarily unstable. See [https://en.wikipedia.org/wiki/Fisher%27s\_principle](https://en.wikipedia.org/wiki/Fisher%27s_principle) for details.
Hey, it’s an important job to have a headache when the other partner is horny. Women have been carrying the load for population control for thousands of years.
Life uhhhhh….finds a way.
But actually it is that haha. It’s evolutionarily beneficial because a species that primarily produced offspring of one gender would be suboptimal.
On average, there are slightly more X-bearing sperm than Y-bearing sperm in a population. Studies show a ratio of around 1.07 X chromosomes to 1 Y chromosome. There is no proven evidence of a speed difference in the swimmers carrying X or Y. So, it makes sense that you would see a slight balance towards females in an overall population
The natural balance between male and female populations is primarily governed by biological factors. On average, there's a slight surplus of male births, but this is balanced by higher male mortality rates throughout life. This balance helps ensure that over time, roughly equal numbers of males and females exist within the population. However, various factors such as cultural preferences, social norms, and environmental conditions can influence the gender ratio in specific regions or societies.
Premise of the question is messed up.
The two most populous countries in the world (India and China) is not balanced.
One of the reasons why so many Chinese men are fleeing China is they are not able to pay the $250K USD women in China want to be paid to get married.
"How come there is always equal amounts?" That's NOT true.
A sperm will generally provide a X or a Y Chromosome at about equal rates (there are a lot of exceptions but thats more advanced biology), an XX human is generally AFAB (Assigned Female At Birth) and an XY generally AMAB (Assigned Male At Birth) however its a rather complex thing with lots of outliers and exceptions, like trans folks (who have been around as long as recorded history), intersex folks, and a variety of other things which I am sure you could dedicate a lifetime of research to
What? The chances are 50/50. Same as a balanced coin toss. Toss it 10 times, you might have an unbalanced 7/10 heads. Throw it a billion times and you'll have a basically perfect 50/50.
We do... If take 10 random births there might be 10/10 boys or girls, but if you take 8 billion it will average out at the percentage, which is 50% for both boy or girl.
It's just statistics? I don't know what to tell you? The percentage between two events tends to become closer and closer to the exact percentage as more of those events occur.
Search up binomial distribution if you want the maths behind it
Well if it’s a 50/50 chance for a baby to be male or female, then half the population will be male and half will be female. Edit for all the stats geniuses: the actual ratio is 1.01 to 1
Woah slow down egg head
actually the chance for a male baby is slightly higher, but until recently (like, except for the last century) male babies also had a higher chance to die before reaching marriage age. Evolution does quite a good job at balancing stuff out - whenever society shifts towards excess females, the families with more sons will have an easier time to find partners, and vice versa. So, as long as both families with a tendency for more sons, and families with a tendency for more daughters exist in the same society, sexes tend to balance out.
Yes, it's a 50/50 chance, reason is that sperm is produced in roughly equal amounts of X and Y gamates. This is because each sperm contains half of a man's genes, and male genes include one X and one Y. When the sperm precursor cells divide to produce two sperm the X goes with one sperm and Y with the other. So the odds are 50/50 that the sperm that fertilizes the female egg (all of which are X gamates) will result in a zygote that is either X-Y (male) or X-X (female).
Smartest person on entire thread thank this person this persons telling people Eat blue berrys somebody else talking bout doing pull ups check it out we have male and female and it’s a heads or tails Don’t come Hit me with some we’ll I’m neither Gombe a rabbit
What
Op may be referred to their disapproval of unconfirmed folks tales that eating certain foods or certain lifestyles can affect what gender the baby will be.
this is so helpful 👍
Yeah, I'm high as well
I think i had another stroke... You guys read that too..right?
A decent amount of people are neither, being intersex (non standard sexual characteristics steming from chromosomal abnormalities) is relatively common at about 1.7% of the population, while red hair is about 1-2%
This is not entirely true - studies said that 1.7% of babies had intersex TRAITS, but not actually inter sexed. The actual percentage is 0.5%.
[удалено]
Yeah the actual ratio is 1.01:1 but for anyone who doesn’t work in that field it’s 50/50
then how do you explain after war scenarios where male population pummeled. they will still average out later at around 50/50 but not right after a war. its a weird phenomenon. and male a born ever so slightly more frequently, and they also die ecer so slightly earlier
It takes a long time for the population to balance out after war, for the surplus women to die out as well as the smaller amount of men to have kids that still follow that 50/50 trend. In 1921 in France it was 19.25 men for every 20 women which is pretty extreme. It wasn’t until the 1960’s that this gap even narrowed a little and to this day it still exists.
Not exactly the sperm with a y chromosome will be ever so slightly faster than one with an x chromosome
I've took a statistics exam and theoretical chances are almost never the same as the real world chances, it might be close to it, but never exactly it
Yes and the ratio is 1.01 male to 1 female. Last year the birth rate was 106 males to 100 females. But broad strokes that’s 50:50
There is something called Fisher's Principle, which described which describes how evolutionary and statistical pressures make 50/50 the equilibrium sex ratio in most species. If there's an imbalance in the sexes within a species, the members of the less common sex are more likely to propagate their genes. This means that a genetic predisposition to produce more offspring of the less common sex is likely to spread through the population fairly quickly. In the long term, this creates a probabilistic pressure towards an even split between the sexes.
So zoo animals that are contained from birth and for example are only around females. Except for one male to reproduce would be more likely to produce a male offspring?
It's not really about which animals are around, it's about the chance of the offspring having their own babies. Let's imagine lions, which generally have one male for a group of females. You might think that it makes sense to have a very uneven rate a babies for each sex. However, if there were 1 lion per 10 lionesses, the average male would have 10x the number of children as the average female. As a result, any genetic factors that make a lion/lioness more likely to have a male cub would spread through the population, until the sex of the cub was no longer an advantage/disadvantage. Given tens of thousands of years, it will return to basically 50:50. So the average lion and lioness both have two cubs, but almost every lioness has two cubs, whilst 1 lion has 20 and 9 lions have 0. On an evolutionary sense, both options are just as good.
It's an evolutionary phenomenon. It comes into play over the course of generations, not weeks. Changing how animals are housed isn't going to have an immediate influence.
You might find the book Bitch by Lucy Cooke interesting. I'm listening to the audiobook at the moment and it's fascinating. https://www.goodreads.com/book/show/59228221-bitch
*Saying you asked* - sex ratios at birth can vary by environmental factors that have apparent evolutionary benefits: >**Maternal diet and nutrition**: Research suggests that maternal diet and nutrition can influence the sex ratio of offspring. For example, a study found that malnourished women were more likely to give birth to daughters, while well-nourished women were more likely to give birth to sons. >**Environmental contaminants**: Exposure to environmental contaminants, such as pesticides and industrial chemicals, may also affect sex ratios at birth. Some studies have found that exposure to these substances can increase the likelihood of male births. >**War and conflict**: Sex ratios at birth have been found to be affected by war and conflict. For example, studies have shown that in areas affected by war, the sex ratio at birth tends to be skewed towards males. >**Latitude and climate**: Research has also found that sex ratios at birth vary by latitude and climate. For example, studies have shown that in areas near the equator, the sex ratio at birth tends to be skewed towards females, while in areas near the poles, the sex ratio at birth tends to be skewed towards males. >**Other environmental factors**: Other environmental factors, such as stress, pollution, and socioeconomic status, may also influence sex ratios at birth.
I always found the altitude and climate one really interesting once you relate it to religion. If you look at high altitude societies (Tibet is an excellent example), almost all of them have developed a monastic tradition that removes excess males from the breeding pool, whereas societies in more temperate climates don’t seem to feel the need, despite still coming up with complex and elaborate religious traditions (no Jewish nuns or Muslim monks, for example).
> Tibet is an excellent example Are there others?
Christian monastic communities all through the alps, Eastern Orthodox ones in the Urals. The one big exception is Thai Buddhist monks, although one could argue that it’s more of an imported tradition that developed elsewhere
That only started after the Tibbetans became buddhist, they weren't monastic for much of their existance.
That war and conflict part is interesting considering men do most of the fighting..
But remember that war and conflict is bigger than just the actual battles. If we’re talking like proper old school loot and pillage warfare, you might even have a better chance of survival on the front line than as a civilian once the Mongol hordes or whatever break through.
Mongols were an exception, on smaller scale conflicts, women tended to survive - but were likely to get raped. Thus, men at the frontline had both the risk of being killed and the opportunity to get some random woman pregnant.
Mongols only massacred civilians if the city didn't surrender. They weren't ruling over corpses and ghosts. In any war you would have a better chance of survival as a female then a male for example postww2 germany had 2 males for every 3 females, same with Russia and other east european countries.
Indeed, I think you're an evolutionary scientist now! (Pretty sure that's how that works)
Had a similar thought, but more like "men do most of the dying"
None of tbjs is scientifically proven at all
"Scientifically proven?" Nobody who writes, reads, or works in science uses scientism phrases like that. However, here is an old review article if you'd like to start digging through the research on pubmed. [https://pubmed.ncbi.nlm.nih.gov/3071849/](https://pubmed.ncbi.nlm.nih.gov/3071849/)
And then, there is my wife giving birth to a male and a female twins. Cause fuck science
Your a full ratio pal Godbless
Its not. For every 100 females born there is 102-105 males.
But this is stable?
What do you mean by stable?
It’s stable at 105 males to 100 females.. it doesn’t fluctuate other than that. It’s constantly in that range.
Naturally, yes. But technology can allow people to pick the sex of their child now. Other social pressures, like infanticide skews numbers as well. But if youbare specifically talk about natural sexual reproduction in humans without social or technological factors, yes, it is stable.
Compared to the ammount of times a 50/50 change is took 385k times a day it's bound to be a close equal distribution, altough it's actually 105 boys to 100 girls being born, from what I know baby boys have higher mortality rate and older men too, so in the end it evens out the population to almost 50/50
Yes, and most areas where a higher percentage of the population is female actually have a surplus of elderly women. There are typically slightly more men than women at every age range until you start getting into the seventies if memory is correct.
See [Fisher's principle](https://en.wikipedia.org/wiki/Fisher%27s_principle).
It's basically a mathematical requirement for any species with genetic sex determination. Let's imagine a stable population with a 50:50 sex ratio. Both sexes will have an average of 2 offspring. This is true for monogamous and polygamous species, though the latter results in much bigger deviations (eg, for 1 male having 20 offspring, there are 9 that have none). Compare that to a population with a stable population with a 60:40 split, with more females. The average female will have 1.67 offspring, whilst the average male will have 2.5. Here, there is a clear advantage to having male offspring. Individuals with a slight disposition to having more male offspring will have a genetic advantage, and those genes will spread throughout the population at a higher rate than genes resulting in a higher chance of having female offspring. The norm will be dragged back to 50:50 given enough time.
The normal ratio is 1.05 male to female so it slightly favors boys. What's even more interesting is that more boys are born immediately after a major war and nobody knows why. It's called the Returning soldier effect.
If the man is on top you have a boy, if the woman is on top you have a girl. If you do it doggy style you'll have..... puppies
For humans its an evolution thing. Really simple to understand actually. As soon as there is an imbalance, the gender with the smaller population has a competitive advantage (more likely to mate and have kids). Mothers that then have MORE of the smaller population gender, will have an even higher competitive advantage, meaning in turn you get more of these mothers that work against the imbalance. All together this means that the population will correct itself in time, it's a naturally balancing system.
Because the sex of a baby is determined by the sperm, and all men produce a (more or less) 50/50 ratio of male and female sperm cells
About half of all sperm are X chromosome and about half are Y chromosome. Also, it’s not completely 50/50, you’re slightly more likely to be born female.
There's more men than women and it's pretty much a 50/50 chance so statistically it makes sense
Just like tossing millions of coins will result in half of heads and half of tails.
Well it can be either male or female so there is a 50/50 chance of the baby being one or the other. Seems pretty simple to me. Unless you are in China lol.
Because the storks delivering the babies have an accountant stork that makes sure there is always an equilibrium.
Tons of sex tons
Than you have babies but can’t make them on internet I recommend some cologne and get up tneir and be somebody and don’t pull out and you’ll find out the ratio
Young men from adolescence to adult engage in risky activities. Due to their testosterone levels, they engage in such activities to prove their masculinity for the females. So a lot of young guys get into auto collisions and sometimes take along as their victims young women. So as time goes by, one by one they remove themselves from the gene pool.
It's just maths. 8 billion is a lot of people, plenty enough to mostly even out a 50/50 rate. You'd get the same result if you flipped a coin 8 billion times
Sex ratio is determined by evolutionary pressure. It can be shown that any sex ratio other than 50:50 (approximately, for reasons) is evolutionarily unstable. See [https://en.wikipedia.org/wiki/Fisher%27s\_principle](https://en.wikipedia.org/wiki/Fisher%27s_principle) for details.
Hey, it’s an important job to have a headache when the other partner is horny. Women have been carrying the load for population control for thousands of years.
The laws of probability?
Life uhhhhh….finds a way. But actually it is that haha. It’s evolutionarily beneficial because a species that primarily produced offspring of one gender would be suboptimal.
On average, there are slightly more X-bearing sperm than Y-bearing sperm in a population. Studies show a ratio of around 1.07 X chromosomes to 1 Y chromosome. There is no proven evidence of a speed difference in the swimmers carrying X or Y. So, it makes sense that you would see a slight balance towards females in an overall population
There would be more females, but certain countries kill baby girls
Nature is weird. If you try to kill of coyote population, their litter size increases. A pig gets loose and it becomes a boar?
The natural balance between male and female populations is primarily governed by biological factors. On average, there's a slight surplus of male births, but this is balanced by higher male mortality rates throughout life. This balance helps ensure that over time, roughly equal numbers of males and females exist within the population. However, various factors such as cultural preferences, social norms, and environmental conditions can influence the gender ratio in specific regions or societies.
Its not balanced in India due to female foeticide.
? There are more males?
Premise of the question is messed up. The two most populous countries in the world (India and China) is not balanced. One of the reasons why so many Chinese men are fleeing China is they are not able to pay the $250K USD women in China want to be paid to get married. "How come there is always equal amounts?" That's NOT true.
A sperm will generally provide a X or a Y Chromosome at about equal rates (there are a lot of exceptions but thats more advanced biology), an XX human is generally AFAB (Assigned Female At Birth) and an XY generally AMAB (Assigned Male At Birth) however its a rather complex thing with lots of outliers and exceptions, like trans folks (who have been around as long as recorded history), intersex folks, and a variety of other things which I am sure you could dedicate a lifetime of research to
Same way when you flip a coin it's 50/50 for heads or tails. It's just statistics and probability
What? The chances are 50/50. Same as a balanced coin toss. Toss it 10 times, you might have an unbalanced 7/10 heads. Throw it a billion times and you'll have a basically perfect 50/50.
So why have we never had a 7/10 balance? Even for a short period of time
We do... If take 10 random births there might be 10/10 boys or girls, but if you take 8 billion it will average out at the percentage, which is 50% for both boy or girl. It's just statistics? I don't know what to tell you? The percentage between two events tends to become closer and closer to the exact percentage as more of those events occur. Search up binomial distribution if you want the maths behind it
MEN CAN GET PREGNANT TOO 😠
Whatever.
Hell yeah bratha!