"We only/don't make boys!"
Updated 12-28-17
We only make boys! We don't make boys! How many times have we all heard that one?
This is one of those things that really get to us because sometimes it FEELS true! But it just can't be the case. Here are the facts.
:prof: Men HAVE TO make 50-50 X and Y sperm. No matter what anyone else says, this is biological fact. http://genderdreaming.com/forum/sper...x-y-sperm.html
:prof:More males than females are born (about 105 boys for every 100 girls) and also conceived (140-160 males conceived for every 100 females). For reasons we can only guess at, 50-50 X and Y sperm go on to produce different rates of offspring and science indicates both males and females have some control over this. http://genderdreaming.com/forum/sway...-part-1-a.html
:prof: Fewer males than females survive to adulthood. This is for a variety of reasons, including increased rates of illness and vastly higher rates of interpersonal violence, up to and including wars. At some points in time this disadvantage became huge. http://genderdreaming.com/forum/sway...advantage.html
:prof: According to DNA studies, of the males that survive to adulthood, fewer have offspring compared to females. Of all the males that have ever lived, only 40% of them have surviving offspring. Whereas of all the females who have ever lived, 80% of them have surviving offspring.
:prof: All throughout human history, and in fact amongst most mammals, it is a very typical occurrence for a conqueror or new "alpha" male to take over and kill off or drive away many or all the men and male offspring that may have been fathered by another individual or tribe. There are thousands of examples of this throughout human history dating back to the earliest myths and legends and it's also very common amongst our closest animal relatives, the primates.
:prof: Even though males are on average less reproductively successful, some males are SUPER successful and are able to pass down genes to many offspring. An example is Genghis Khan, whose genes are carried by an estimated 8% of all Asian males and the Hapsburg family who married into all the royal families of Europe during the middle ages.
:prof:Even though females are on average more reproductively successful than males, even the most successful female reproducers are biologically unable to have as many offspring as the most successful male reproducers are. Michelle Duggar may have 19 children, but "Ismail the Bloodthirsty" is believed to have a minimum of 888 and possibly over 1000 offspring by wives and concubines https://www.psychologytoday.com/blog...y-888-children
:prof: Genes are passed down from generation to generation. Those that are successful are passed down to successive generations and those that are less successful, die out over the course of time.
:prof: Given the above facts, it makes NO evolutionary sense for a family to "only make boys". A family that "only made boys" would be tying their entire genome to a gender that starts out life more likely to die from the moment of conception onward, has on average far less chance at reproduction than females do, and runs the risk of being completely wiped off the face of the planet at any moment - the first time Genghis Khan comes to town and kills off all the males, that's it, game over. No more offspring. Those genes would have died out a long time ago.
:prof: It makes NO evolutionary sense for a family to "only make girls". A family that "only made girls" would be tying their entire genome to a gender that is less likely to be conceived in the first place, cannot have as many children as males are able to, and are unable to capitalize on extreme situations where one individual (such as Genghis Khan or Ismail the Bloodthirsty) is able to produce vast numbers of offspring - or even less vast like these guys The 20 Biggest Illegitimate Fathers In Sports | Bleacher Report
:prof:It makes the most sense for individuals to have the gender of offspring that has the best chance of survival to adulthood to pass down genes http://genderdreaming.com/forum/gend...ypothesis.html. Thus, because "only making boys/girls" does NOT make evolutionary sense, and being able to alter the gender of your offspring on a case by case basis depending on which gender has the best shot of surviving to adulthood and finding mates to pass down their genes, does make evolutionary sense, it's far more likely that all humans have the ability to alter the gender ratio of their offspring accordingly.
:prof: It is all but impossible for such a gene to have evolved anyway because if it did, the gender ratio would start to become so skewed within only a few generations (meaning that so many of one gender would be conceived that those individuals could no longer find mates) it would become a huge disadvantage and start to become selected against.
Individuals of the opposite sex, and therefore without that gene, would then have a reproductive advantage because suddenly they'd be in high demand as a potential mate.
This idea, called "Fisher's Principle" has actually been investigated by many scientists for over a century and has been proven in a series of mathematical simulations to be true.
According to Fisher's Principle, regardless of what gender you start out with, the following happens:
Suppose male births are less common than female (or vice versa could be true, let's just stick with males to reduce confusion).
A newborn male then has better mating lifelong prospects than a newborn female, and therefore can expect to have more offspring. (because males are less common, they would be rare and precious and gals would be lining up to "tap that" LOL)
Therefore in this scenario, parents genetically disposed to produce scarce males (even at 50-50 ratio) would tend to have more than average numbers of grandchildren born to them, because this smaller number of males that carries the "boy genes" would have more offspring than the average person who lacked this imaginary gene.
Thus the genes for male-producing tendencies spread (even if only 50-50!) and male births become more common. The imaginary "boy gene" would spread like wildfire through the population.
As the 1:1 sex ratio is approached, the advantage associated with producing males dies away, because now there are an equal number of guys and dolls, the advantage of rarity goes away.
The same reasoning holds if females are substituted for males throughout. Therefore 1:1 is the equilibrium ratio. Forces of genetic selection, over the course of time, have worked to stabilize the gender ratio at about 50-50 for most animals and that is why most animals have roughly 50-50 male to female ratio.
:prof:EVERY time that someone has come to me with incontrovertible proof that their family "only makes boys/girls" for 1 or 2 or 3 or 1 zillion generations, upon further investigation, there is invariably some branch of the family that is left out well...except for the cousins, many times we later learn that some of these people are not even genetically related to each other, or "it skips a generation" or "only one girl per generation" or so on and so forth. Some nonsensical explanation is always given to explain away the girls (or boys) in the family.
People love to look for patterns and trends and have the tendency to overlook things that do not fit into their theory. These things simply don't hold water, though. Do some families seem to have more of one gender than another - YES, they do. But it isn't genetics, it isn't set in stone, and says nothing about YOUR chances of having a girl or a boy!!!
Also please read the other part of this double essay here: http://genderdreaming.com/forum/sway...f-that-gender=
