One and a Half Natures of Humans – 14. Questions About Female Reproductive Biology
https://batrachos.com/1_5_Nature_PromptAboutWomen The course is based on general material about the evolutionary mechanisms of behavior, but may also include discussion of the most interesting topic—our own traits and their causes. A good starting point is female reproductive biology.
Questions about Female Reproductive Biology Humans are a species that adapts to its environment in a way that is very unusual for other animals. According to Dennett's classification, we are "Gregarious animals": we adapt to the environment by using models that we build together using "tools" such as language or science. In addition to changes in the mechanism of evolution, Homo sapiens Linnaeus, 1758 exhibits interesting changes in reproductive biology, including, among other things, the functioning of the female body. Is this a mere coincidence, or are our culture and changes in female physiology somehow related? The most likely hypothesis is that the biological changes that occurred in the later stages of our evolution are closely linked in a cause-and-effect complex. Let's formulate a few questions. Question 1: Why do females display attractiveness in humans? In most species with sexual reproduction, males expend energy to become attractive to females. Lions grow manes, nightingales sing, peacock spiders dance for females, bowerbirds build bowers for females... Females watch the males trying to attract them and make their choice. Why is this so? Why do females make the choice in most species? And in humans? How much time do women spend on makeup, and how much do men spend? Why? There are known examples of situations where men spend a lot of time and effort changing their appearance; it seems that in most of these cases, these changes are intended to impress other men, not women. Why? External attractiveness and beauty, signs of youth and fertility – qualities that are usually demanded of women among humans (this is a statement of what happens in many cases, not how it should be). Why? Who makes the final choice in humans in most cases – a woman or a man? In our closest relatives, chimpanzees, mammary glands are enlarged – a sign that leads to a loss of sexual interest in females by males. This is evidence that the female is breastfeeding and is incapable of fertilization. In humans, mammary glands are enlarged all the time and are an attractive feature for most men. Why? Question 2: Why did estrus change to menstruation in humans? Our species is characterized by profound changes in female physiology. Each of these changes occurs in only a few other animal species (while, it seems, only in ours). One of them is the replacement of the estrous cycle with the menstrual cycle. Do you understand the difference? Estrus (heat, rut) is a marker of ovulation when the female is receptive and can become pregnant. Menstruation is not related to ovulation; it conceals it. Why did such strange changes occur in humans? Question 3: Why do women lose the ability to reproduce at a perfectly viable age? Another peculiarity of human female reproductive physiology is menopause. In most species, the main purpose of an individual's existence is reproduction. When an organism loses the ability to reproduce, it soon dies. In humans, the ability to reproduce is lost differently in representatives of different sexes. Men can lose fertility due to various diseases, but normally they retain it into old age (with a gradual decline, the reasons for which are also interesting to consider). Women, who still have a lot of life to live, undergo significant hormonal changes (menopause) and lose the ability to reproduce. Rare cases where this does not happen are anomalies. After menopause, healthy women can live for decades, have sex, but do not get pregnant or give birth. Why?