What can happen in human society when 'the gender of a child born changes depending on the temperature'?
Some crocodiles and turtles have a phenomenon called temperature-dependent sex determination (TSD) in which the sex of the child changes depending on the environmental temperature around the egg, and the sex of the child born changes depending on the temperature. Live Science, a scientific media outlet, summarizes the question, 'What can happen if the sex of a child born to humans changes with temperature?'
What if temperature determined a baby's sex? | Live Science
Human sex depends on the X and Y sex chromosomes , but in some reptiles such as crocodiles and turtles, the ambient temperature during egg development determines the sex of the child. This phenomenon has been known since the 1960s, and in recent years, the problem that 'the proportion of females in newly born sea turtles is increasing due to the effects of global warming' has emerged.
What causes the number of hatching sea turtles to become female? --GIGAZINE
According to Arizona State University biologist Karla Moeller , sex can change with temperature because heat and cold affect sex hormone secretion in temperature-dependent sex-determining animals. Especially in red-eared sliders , the amount of an enzyme called 'aromatase ' that converts male sex hormones into female sex hormones increases as the environmental temperature rises, so it is thought that the higher the temperature, the more females will be born.
It has been pointed out that the reason for the development of temperature-dependent sex determination in reptiles is related to 'the warmer the egg temperature, the faster the embryonic development'. Eggs with a higher environmental temperature hatch faster, so there is a possibility that 'the sex that is more advantageous for the survival of the species' will be born at a higher environmental temperature, and another sex will be born at a lower temperature. .. For example, if it is convenient for an individual of one gender to be larger than the other at maturity, the gender that wants to grow larger may be born at a higher environmental temperature.
Another reason is that temperature-dependent sex-determining organisms 'can choose the gender of the majority in the next generation, depending on the context of the population.' In the case of animals that produce males when the environmental temperature is high and females when the environmental temperature is low, it is possible to lay eggs in a cool place to increase the number of females when the population is small, so that the next generation will lay more eggs. is. In addition, when the number of individuals is sufficient, it is possible to lay eggs in a warm place to increase the number of males and induce stronger and better males to mate with females.
heterothermic is. On the other hand, human beings are warm-blooded animals in which the child grows to a certain extent in the mother's body and can keep the body temperature constant regardless of the ambient temperature. Not applicable.
All known animals with temperature-dependent determining is oviparous, a change in body temperature by the surrounding environmental temperature
Diego Cortés, a biologist at the National Autonomous University of Mexico, said, 'Temperature-dependent sex determination requires two types of temperatures:'body temperature that produces a male foetation'and'body temperature that produces a female foetation.' However, since human body temperature is always constant at around 37 degrees Celsius, temperature-dependent sex determination in humans is unlikely to occur. '
Even so, if the human body can sense subtle changes in temperature in some way, the possibility that the temperature will change the gender of the child is not zero. For example, proteins that control human circadian rhythms sense changes in body temperature in animals and may be involved in temperature-dependent sex determination in reptiles, Cortez said. Also, even if it is a mammal, if it is a poikilotherm like the naked mole rat or an oviparous like a platypus , the sex of the child may change depending on the temperature.
Jennifer Graves, a geneticist at La Trobe University in Australia, points out that if humans had temperature-dependent sex determination, it would be easier for parents to give birth to their children. He argues that this can be a problem as it increases the imbalance between men and women in society.
'Many people like to determine the sex of their children. Sadly, the preferred gender in many parts of the planet is male,' Graves argues, as mothers change their body temperature to make their children. If the gender of the child can be changed, it is highly likely that many of the children born will become male. To prevent this, Graves said a rule would be needed, such as 'If you change your body temperature during pregnancy, you must do it after your gender is determined.'
In addition, if one of the adult populations has an excessive number of genders, there is a risk that violence and sexual conflict will increase and social harmony will occur. Furthermore, even if the government bans the birth of children, external factors other than parents can affect the gender of the child, resulting in a gender imbalance in social groups.