Why hasn t morning sickness been eliminated in evolution?

It is now generally accepted that morning sickness.

Far from being a harmful phenomenon that hinders human adaptation to the environment, it is precisely a defense mechanism that human beings have acquired in evolution. In short, morning sickness both prevents pregnant women from eating foods that are harmful to the fetus and prevents low immunity.

of pregnant women received pathogens in food.

hazards. In order to prevent predation, a large number of plants contain toxins. In adults, organs such as the liver produce large amounts of detoxifying enzymes to break down these toxic substances.

However, in the fetus, these defense mechanisms are far from mature, and trace amounts of plant toxins can cause serious or fatal harm to the fetus. One of the effects of morning sickness is to cause a vomiting reaction when pregnant women smell and taste foods that may contain these plant toxins, so as to avoid harm to the fetus. This theory is confirmed by a number of facts:

Plants with high levels of toxins produce smells and tastes that are more likely to trigger morning sickness;Morning sickness is usually worst around the third trimester of pregnancy, which is when the fetus is most sensitive to plant toxins. Studies have shown that pregnant women who do not have morning sickness are generally more likely to have a miscarriage. In addition, in order to protect the maternal immune system.

Recognizing the fetus's tissues as invaders usually suppresses a pregnant woman's immune system. As a result, parasites contained in animal foods.

With bacteria it will be easy to cause harm to pregnant women. The reason why animal products such as fish and meat often cause morning sickness is probably because of the defense mechanism against this class of pathogens. All in all, morning sickness is not a phenomenon that goes against the evolutionary trend, but an instinct that goes with the evolutionary trend. <>

Natural selection seems to have shaped a mechanism by which the health of the mother is sacrificed for the benefit of the fetus. - Nice & Williams In 1992, the American biologist Maddy Profe wrote an article in the book "The Adaptive Mind", entitled "Pregnancy Response as an Adaptive Mechanism: Limiting the Mother's Intake of Teratogens".

The article suggests that a near-universal and spontaneous phenomenon such as pregnancy reaction is unlikely to be pathological. She noted that the period when the fetus was most vulnerable to toxins almost coincided with the period of pregnancy reactions of pregnant women. The fetus is most susceptible to toxins around the same time, and the period when pregnancy reactions are most intense is also around the same time.

Profe thus proposed the "antiterratogen theory": pregnancy reactions, such as nausea, vomiting and anorexia, may be aimed at minimizing fetal exposure to toxins and preventing aberrations and malformations. In the first trimester of pregnancy, i.e. the first few weeks of pregnancy, the nutritional requirements of the embryo are small for the mother, and even if a woman of average health eats less, it will not affect the nutritional requirements of the embryo.

What is terrible is food poisoning and the resulting aberrations and terratosities. At this time, pregnant women tend to like to eat relatively light foods that do not have strong smells and tastes, and the strong smells and tastes are precisely the toxins released from the food. They dodge not only the toxins of spicy plants, but also the toxins produced by the decomposition of mold and bacteria.

Therefore, this kind of human body "design" will not only not be eliminated by evolution, but will be retained, which is the beauty of evolution, and the more you advance, the more beautiful it becomes.

Morning sickness is actually the mother's rejection reaction to the fertilized egg, the larger the reaction during pregnancy, the higher the miscarriage rate of the fetus, and it is not good for the mother to not have a child too early after marriage.

Isn't it too much to say that you can't drink water? What to protect? Protect yourself from going to heaven? If I hadn't stumbled upon drinking red bean water and not throwing up, I would have died.

The act of vomiting is the most intuitive response of the body to instinctively repel foreign bodies.

I vomited all the time during my two pregnancies, and I vomited until I was about to give birth to a baby, and the vomit that turned over the river and the sea really vomited to doubt life.

The twin babies barely threw up except for some retching before going to bed at night, and they were intimate little babies.