Introduction: Why haven't females evolved anti-rape mechanisms?
The law of survival in nature is survival of the fittest, but the animal world under this law is very complicated, some of these animal species in the female side is stronger than the male side, such as the tiger shark, although they are all sharks, but the female tiger shark can eat the male counterpart as a delicacy, and even eat the male counterpart after mating.
Some animals will also eat males directly on the spot, such as red-backed spiders and black widow spiders, and after mating, the females don't care about the death of their male kind as if they have eaten a delicious meal, so we can deduce that female animals are not born possessed by males.
However, the mating behavior of most animals is that males actively pursue mating, and females are in a state of passive defense, especially in amphibians, and the passive resistance behavior of many female frogs has even been summarized into a series of anti-rape mechanisms.
Recently, there is a special kind of frog that has attracted people's attention, and they will even choose to play dead directly to avoid the pursuit of males, what kind of frog is this?
How did the female frog's resistance evolve?
The emergence of "female predators".
In nature, courtship is an important part of animal reproduction, especially in the spring when the nutrients are abundant and the environment is pleasant, and animals will do their best to courtship in order to reproduce their offspring.
In the animal world, the initiative of courtship is generally in the hands of the female, because the cost of male germ cells is much greater than that of a few egg cells in a careful egg, and male animals can produce a large number of sperm per milliliter of semen, and only a few of them can successfully enter the female body and hatch into offspring.
Although there are some animal species in which females are active, in most animals, males actively pursue, and females passively choose mates are the vast majority, which is related to the cost of germ cells, sperm is cheap, and egg cells are expensive.
In other animal species, females are even more aggressive, and males need to be careful not to provoke females to be eaten, because females are larger and stronger, and are not afraid of being pursued by females for mating.
For example, the female is larger than the male and is very sensitive to food sources, during the breeding season, the female will remember the places she has been, and when she comes back to hunt again after giving birth to the calf, the male will become a delicacy for the female bull and tiger shark.
Animals tend to use a very diverse variety of techniques when reproducing offspring, with courtship being the most common, but as a result of thousands of years of natural selection, experienced females have bred their offspring over multiple generations, simplifying the skills to resist courtship and gradually developing anti-rape mechanisms.
Originally, there were various ways to resist courtship, for example, the female frog would use her call to attract male frogs of the same species, and when the female and male frogs met, the female frog would quickly roll over, imitate the sound and smell of the female frog, and disguise herself as a female frog, so that the male frog would mistake the female frog for another male frog and try to mate, and the female frog would take the opportunity to escape.
Some animals will disguise themselves as females who have already mated to shield males who are passively standing guard, so that other courting males will have an advantage over other sperm, increasing the success rate of mating.
In this way, the anti-rape mechanism was not invented by intelligent animals when they were trying to survive, but the female gradually evolved after several generations of breeding offspring of each species, which shows that the difficulty of resisting courtship during reproduction is low, and the success rate of resistance is still very high.
The anti-rape mechanism is also effective, because the success rate of mating after successful courtship is low, because the number of sperm in the male is so large that it is impossible for every sperm to successfully enter the egg cell in the female's body.
As a result, although the number of male frogs mating with the female after the female sends a courtship signal is large, the number of successful offspring is still very small, so that the anti-rape mechanism successfully promotes the transmission of female frog genes.
This shows that the female frog's rebellious behavior is meaningful, and the anti-rape mechanism helps the female frog to improve the success rate of offspring, and in this sense, the female frog becomes the "natural enemy" of her offspring.
The amazing move of the frog in France.
In nature, the defiant behavior of female frogs has attracted attention, but recently there is a special kind of frog that will even choose to play dead directly to avoid the pursuit of males, what kind of frog is this?
When scientists in France investigated the breeding behavior of frog populations around France, they found that frogs in populations near the channel between United Kingdom and France actually lowered their pitches when breeding, which even aroused curiosity.
The researchers took a closer look at the frog and shocked everyone to find that the frog would play dead while waiting for a male to court!
The discovery of a low-voiced frog's resistance to courtship has never been discovered, and the discovery has shocked researchers, with many saying they can't figure out how a female frog can make a male frog give up mating by pretending to be dead.
To the researchers' surprise, after discovering this strange act of resistance, they observed other frogs and found that the female frog also pretended to be dead and courted.
So this question aroused the interest of researchers, and people began to speculate, how did the female frog manage to play dead?
What are the benefits of playing dead?
This new discovery brings new questions to the table, but it also makes people even more amazed by the wonders of the natural world.
Excessive aggressiveness of male frogs.
This kind of feigning death is relatively rare in animals, and it is usually achieved by venting the breath, stiffening the body, and even stopping the heartbeat if necessary, so that the predator can ignore it.
In the previously mentioned female's more aggressive predators, the female may actively attack the predator, and the dominant female has absolutely no room to play dead.
It is even more strange for frogs to pretend to be dead, because the frog's neck structure is very special, when the frog inhales, the lungs expand, and the muscles behind the diaphragm also contract, causing the spine to bend forward, so that the frog can inhale air forward and expel it backwards.
But when the frog pretends to be dead, it must stop this normal life activity, completely relax the muscles, and finally cause the frog's heartbeat to stop, and the frog's whole body is as hard as a stone and no longer moves, how does the frog do it?
The reason why the female frog is playing dead is also curious, as there have been previous cases of frogs rolling and imitating their calls, leading researchers to believe that the female frog may well be able to play dead.
But if you don't look closely, you really don't know that playing dead is actually a good way for frogs to resist courtship, so scientists studied the female frog's attempt to play dead, and came to the conclusion that playing dead female frogs can deceive male frogs and make male frogs give up mating faster.
But after all, the female frog is alive, and the female frog can't pretend to be dead for too long, otherwise it will be dangerous, not to mention that the way to pretend to be dead is relatively simple, the female frog can pretend to be dead at any time, but it will be difficult to resurrect.
The researchers also investigated the mating behavior of frogs and found that male frogs behaved aggressively during the breeding season, and sometimes when females appeared, males would even mistakenly hug other species, or even more than one frog species, which is clearly closely related to the behavior of females.
The female frog's resistance to courtship is very efficient, and the male frog can't suppress himself during the breeding season, and the female frog may pretend that the male frog is dead by imitating sounds, and then pretend that it didn't happen, and wait for the male frog to leave before mating with other male frogs.
Conclusion: How come females haven't evolved anti-rape mechanisms?
Although no one can say exactly how frogs evolved, in general, the ancestors of frogs were archaean amphibians that inhabited land and waterside and gradually evolved a strong ability to survive, eventually evolving frogs.
If frogs can evolve anti-rape mechanisms, can't other animals?
Further cooperation is needed in cross-species research, and the anti-rape mechanism of frogs promotes the evolution of avoidance ability of offspring to a certain extent, which is likely to be prevalent in a variety of animal groups.