"Processed Products" of Life: Male Physiological Weaknesses as Seen Through Chromosome and Gonadal Development
Even more remarkably, an egg may combine with a sperm carrying a Y chromosome to form a zygote with XY sex chromosomes. However, this alone is not enough to create a male. Around the 8th to 9th week after fertilization, a certain gene on the Y chromosome, under the influence of the male hormone testosterone, forms a testis-determining factor. This factor acts on the primordial gonads (the prototype of the reproductive organs), causing them to differentiate into testes. Only then can the zygote develop into a true male.
[Translator's Note: Embryonic sex development involves two processes: sex determination and sex differentiation. The gene on the human Y chromosome that determines testicular differentiation is called the testis-determining factor (TDF). The TDF is located in the sex-determining region (SRY gene) on the short arm of the Y chromosome. In mammalian embryos, the gonads naturally develop in the direction of female genitalia; that is, female genitalia development does not require sex-determining genetic factors, while male genitalia development requires the TDF gene and the action of male hormones.]
On the other hand, if the fertilized egg lacks a Y chromosome and cannot form the testis-determining factor, the primordial gonads will continue to develop according to their original form, differentiating into ovaries, and the fetus will become female. So what does this mean? Tomio Tada, a former professor at the University of Tokyo's Faculty of Medicine, pointed out in his book "The Meaning of Life" that "humans were originally designed to be female."
The basic human form is female; males are only able to become male thanks to the TDF gene (testis-determining factor). Therefore, men are essentially products of female transformation. This transformation is also evident in the sex organs. The male penis has a longitudinal seam, which is said to be a trace left by the closure of the vagina during the formation of the sex organs.
Men are individuals artificially created from what should have been women. This is also why men, as individuals, have far less vitality than women. They are also less robust in protecting the next generation. Rather than being less robust, it's more accurate to say they lack patience and give up quickly. The same is true of my pair of dwarf chickens; when the hen starts incubating the eggs, the rooster immediately stands guard beside her.
The moment I enter the henhouse, the rooster immediately raises his comb and crows angrily. However, if I merely tap him lightly with a stick, he immediately runs away, making me want to yell at him: "What was that show of defiance all about?!" But the hen, no matter what happens, won't run away. Whether I hit her with a stick, pull her tail, or try to move the entire henhouse, the hen remains unmoved, continuing to incubate her eggs.
Females, who bear the heavy responsibilities of pregnancy, childbirth, and childcare, have a strong sense of mission to protect their offspring's lives above all else, no matter what happens. Males, on the other hand, are essentially useless once mating is over. Because males do not have the responsibility of procreation and childcare, their mental structure differs from that of females; they will not risk their lives to protect the next generation. Human males do not exhibit the same level of vulnerability as male animals.
However, compared to women, men are far weaker creatures. Women can endure the pain of childbirth; if it were a man, almost all of him would have fainted long ago. Men also cannot tolerate the sight of blood. I used to work at a blood donation van, and those who would suddenly faint during blood collection were all men. The reason men appear "strong" to us is because they are taught from a young age that "men must be strong."
However, men are actually much weaker than women biologically. It's practically a case of "weakness, thy name is man."