In nature, males and females constitute both sexes, while sexual selection ensures the quality of reproduction of bisexual animals, and the population size has grown. Human beings are no exception. Men and women choose mates as well as sexual choices.
Research shows that humans will also choose spouses based on their appearance, sound, behavior and other characteristics. For example, women with slim figure, small waist and hips are more popular with men than , and low BMI, which indicates that women are young and have high reproductive potential and other information. On the contrary, women also have sexual choices for men, and they are more picky than men's choices.
Women are more picky than men. What is the scientific basis for choosing a mate?
A study published in the Journal of the National Academy of Sciences shows that men generally value women's appearance when choosing a date, while women pay more attention to the other party's "comprehensive strength".
Before the trial began, all participants filled out questionnaires on mate selection criteria, including family responsibilities, appearance and temperament, health status, wealth and status, etc. The questionnaire results show that most people expect to date their "like-minded" opposite sex.
However, the subject was quickly slapped in the face by the next test. The researchers arranged 26 men and 20 women to participate in the "Quick Pairing" event, and men and women had one-on-one conversations, and exchanged conversation subjects every 3 to 7 minutes. After all participants complete a round of conversations, each person will choose the opposite sex they want to date the most. If both men and women are both consenting and willing, arrange a second date.
After the conversation, men generally chose with a beautiful appearance in , while women were interested in , who was more capable, richer, and more secure. It is worth noting that among the 20 female college students,
Why is there a huge gap in sexual selection strategies between men and women? On the one hand, this is because there are differences in the types and quality of gametes produced by men and women. The sperm produced by men is about 60μm long and can reach tens of millions of levels. The diameter of women's eggs is 0.2mm, and only one single ovulation is discharged.
The energy input of eggs is higher than that of sperm. The difference in the quantity of the two causes eggs to become a scarce reproductive resource. Correspondingly, women naturally have higher right to sexual choice.
On the other hand, female animals pay more for sexual reproduction. From a biological perspective, mammals' sexual reproduction is processed by mating, pregnancy, and childbirth. Female animals in pregnancy and nurturing are more likely to be preyed by natural enemies, have a lower survival rate, and raising offspring also requires more resource support.
The same is true for humans. Women during pregnancy rely on men to provide resources and care. The difference is that human women also have to face problems such as raising, education, and medical care for offspring. Therefore, in addition to paying attention to "high-quality genes" when choosing a spouse, women also tend to pay attention to "high-quality resources", such as: the man's economic strength, education level, social status, etc.
Female animals: How to choose the best spouse?
Darwin proposed the sexual selection theory in "Evolution and Sexual Choice", which divides the sexual selection of animals into two categories: one is the characteristics produced by similar animals to defeat their opponents, such as: the fighting organs of male animals; the other is the characteristics that attract the opposite sex mates, such as: the bright feathers and agile singing voices of birds.
When choosing a mate, female animals either choose strong males or males with good traits, but the ultimate goal is to choose high-quality genes. According to the " signaling model " theory proposed by Andersson, the quality of animal genes can be expressed through certain signals, including vision, smell and hearing. The blue-top blue-breasted croaker is a classic example. Its dance steps are as high as 50 times per second, and its performance is full of rhythm. This is also the "must-examination subject" for the male birds courtship.
Tap Dance Bird's Courtship Performance
More studies have shown that the mating behavior of animals is far more complex than imagined. The choice before mating can be divided into at least five aspects:
Similar phenomena exist in the insect world: the black small hair pattern has the habit of flying in groups, and larger male mosquitoes gather at the bottom of the mosquito population, while female mosquitoes often fly in from the bottom, making it easier to obtain high-quality mating objects.
An ancient amber is wrapped with male insects and their food balls
But there are exceptions in everything. Some animals do not follow the rules of the game, but seek benefits through deception. In order to mating with females, some spiders use spider silk to fake food to deceive the females, thereby defrauding the right to mating.
Australian textile womb with seminal vesicles
Scientists have discovered that mating is not the end point of sexual selection
Mating and reproduction are the core topics of life continuation, but mating is not the end point of sexual selection. Scientists have found that animals also have a "sperm screening" program after mating, which is specifically divided into selection of before fertilization and after fertilization.
Before fertilization, there is still fierce competition in animal sperm, and the competitive strategy is amazing. Some primates and rodents have a special structure of " mating plug ". After mating, male animals leave mating plugs in the female's vagina. On the one hand, it can prevent the semen from flowing back and improve the success rate of fertilization, and on the other hand, it can prevent the female from mateing with other males.
Animal mating plug structure
Male damselfly has more special competitive strategies. Its penis has dual functions. One is to transport sperm, and the other is to remove sperm left by other males through physiological structures. The final result is obvious: excluding dissidents and improving their own reproductive rate.
After fertilization, many female animals still have the right to choose whether to live or not.
Scientists have found that after the female deer rat , meadow voles , lemming lemming and other animals get pregnant, if they are exposed to unfamiliar male rats or their odor for a long time, the fetus' miscarriage rate will increase, and female mice tend to masturbate with new males. This phenomenon is called Bruce effect , which is essentially a pregnancy termination phenomenon.
In addition to rodents, this phenomenon also exists in animals such as lions, baboons, and . So, is this effect good or bad for females?
Take the lion as an example. The young male lion defeats the lion king and replaces it, and the next step will kill the lion's cub to make the lion estrus go back. If the lioness is in pregnancy, it can avoid wasting investment in offspring by termination of pregnancy, which results in greater benefits outweigh the disadvantages.
summary
The sexual choice of female animals is full of magic and mystery, and there is competition and test before and after mating. In order to obtain a spouse, males and females both fight each other and cooperate with each other to create a diverse reproductive ecology.
Compared with animals, human women are also quite picky about their spouses, but the final result is to ensure the competitiveness of offspring and achieve healthy continuation of genes.
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