Is there a scientific reason for there being more women in the world than men?

Question

And have there always been more women or is it just like that this century?

Answer 1

The main reason is that women are less likely to
die than men. The birth rate is not equal, there are
about 105 births of males for every 100 of females. The XY sperm, being slightly less massive, are more likely to be first to the ovum than the XX sperm. (Incidentally, we do NOT all
start out as females. We start out neutral, and the
sex we ultimately develop is dependent on several
things. However the female form is a default form.
If a person has a Y chromosome, which normally
produces a male, but for some reason does not
produce male hormones, that person will be born
as an apparent female, but will be sterile.)

After birth the excess of males is gradually whittled
down by disease, exposure to more accidents,
acts of violence, etc., so that eventually there are
more women left living than men.

Answer 2

Perhaps it is because of the construction of the chromatids in the male zygote (sperm). As you may know, a XY chromosome is needed for a male offspring, while a XX chromosome is needed for a female. So the Y chromosome is the unique factor here. The problem is that the Y chromosome has some fragile spots in its structure. Thus any variance in temperature, exposure to ionizing radiation, or ceratain chemicals can break the Y chromosome, making it non-viable. This creates a higher ratio of viable female zygotes to viable male zygotes. As an example of this, sailors commissioned on naval vessels with nuclear reactors, especially those in the engine room have a higher percentage of daughters than the general population. I am a nuclear pharmacist, my wife is twenty-one weeks and we just discovered we're having a daughter!
Perhaps developments in the 20th century and the industrialization of countries has contributed to an increase in female children. There are many occupations these days in which men (since they are the deciding factor in offspring gender) are subjected to environs that could defect the Y chromosome.

Answer 3

I dont believe your statistics--and most of the poor countries have the contrary figures with female foeticide in a large part playing havoc with the balance---and thats where the population of the world is concentrated. At some of these places, the gender imbalance has been as steep as 100:70 in favour of males. So if you are going by some book covering a few developed countries, better look at the stark truth. Perhaps UN figures will tell you a better and correct figure.
As far as the chances of having a boy or girl, most of the people answered correctly already. I only add that I tend to agree with the gentleman (or lady?) who wrote that chances of getting X-Y is more than a X-X or a Y-Y, and so more girls.

Answer 4

There are two scientific reasons:
1 - Women life longer on average then men do. This probably has to do with the fact that women often can help their children raising their children.
2- When humans have a lot of wealth we can have more children (we can afford to have more children), but we can only have more children if more women than men are born. One man can get a lot of women pregnant, but a woman can only give birth roughly once a year between her 14th and 45th. Thus more women are born then men.

So to answer your second question, the percentage of women will most likely go down if our wealth goes down. We then will need more men to do tough jobs and we will have less children.

Answer 5

Take into account the fact that mens have always been fighting and massively diying at war while women were kept for the reproduction. The situation was even critical after the last world wars where in many villages and towns, all the valid young men were sent up front and the local affairs and production were runned by women. Remember, it brought women's emancipation in the USA...

Answer 6

If you look at the percentage of males conceived it is much higher - the embryonic\fetal mortality for males is much higher and at birth it has almost leveled out at the 105 m to 100 f that has been listed . Then males traditionally have been more prone to getting killed off - they are bigger risk takers, the hunters and fighters. Females the main risk is child birth. With modern civilization coming about this is minimized and other than women still tend to have longer lifespans there isn't as much as a difference.

Answer 7

Maybe there is no scientific equation to express this but 'nature' itself determines the success of a gender. Those not believing in a natural way of things may take the view that there is no one solution to this question but depends upon time, location, environment and social/ cultural factors.

Answer 8

Strangely, there was a huge spike in male births twice last century, once for a year before WWI, and again before WW2. Weird, but look it up if you don't believe me.

Answer 9

my friend check the chines and Indian reports, in those countries the future .ll show the opposite.chenez already have problems they have more men than woman,ultrasound give people to discover what baby is before getting born and harm him if he is girl, what is this ?people in india prefer to have boy not a girl and in many countries either.
all the best .
AL.SELWIY

Answer 10

Well I heard that our genetic material Y it's shrinking, the numbers of genes is falling. This process will continue until it's disappearing. If this is true than we are in danger to vanish from this world.