Animals have a gender, but why the old man said mules do not distinguish between male and female

In the rural areas of our country, many sayings are embedded in thousands of years of inherited experience. One of these sayings is that mules do not distinguish between males and females. This statement is contrary to our common sense, common sense, but it seems that all mammals, will be divided into male and female, but why would there be a "mules do not distinguish between male and female" statement?

The mule is not divided into male and female?

Mules are divided into males and females. But both male and female mules have no way to participate in reproducing offspring. In other words, although it is a male mule, it can't do what a male should do, and similarly, although it is a female mule, it can't do what a female should do. So why is this the case?

First of all, we need to figure out what is male and female, or what exactly male and female refer to.

Male generally refers to the sex of the one that is exclusively responsible for making sperm in a creature that reproduces in both sexes. In contrast, the sex of the one producing the eggs is female. Therefore, in this mode of reproduction of the two sexes, to reproduce, it is necessary to be a male and a female for mating, and not a single male or female self-reproduction.

The male mule is unable to produce sperm, and likewise, the female mule is unable to produce eggs. Therefore, male mules and female mules will not be able to reproduce their offspring. Therefore, there is no point in classifying mules as male or female. There is an extremely low probability that a mule will reproduce, but the probability is negligible. Therefore, the rural areas in the years of experience will come to the "mules do not distinguish between male and female" statement.

Then the question arises, why male and female mules can not produce sperm and eggs?

The origin of mules

To understand this question, we must first figure out: how did the mule come to be?

Generally speaking, when we want to breed a dog, we will use a male and a female to breed. But that's not the case with breeding mules; after all, a male and female mule can't produce offspring. So how do people breed mules?

Generally speaking, people will use male donkeys and mares to crossbreed to get horse mules, which are often referred to as mules. There is another kind is to take the male horse and female donkey crossbreeding get donkey mule. In the past, people did not have anything to take two different species to crossbreed, there is a reason for doing so.

Both horses and donkeys were used for transportation or transport in ancient times. And then people found that if the horse and donkey crossbreed get a mule, mule reproductive capacity, although very poor, but vitality and disease resistance is much higher than the horse and donkey, and eat less than the horse and donkey, physical fitness, the body is very strong, especially the hooves are very strong and powerful, endurance is also very good, temperament is also good, easy to drive, and even can be used as traffic or transport for a longer period, based on so many advantages. Based on these advantages, people began to breed mules to replace donkeys and horses.

The mule has the appearance of a horse and a donkey, with some horse characteristics and some donkey characteristics, but it is not considered a separate species. The most basic requirement for a species is the ability to reproduce offspring, which the mule is unable to do.

The horse has 64 chromosomes. In the process of reproduction, reproduction will be meiotic, and the sperm and egg will have 32 chromosomes each. Then after the stallion and mare mate, the sperm and egg will combine and return to 64 chromosomes.

Similarly, donkeys have 62 chromosomes, and their germ cells will also meiotic, with 31 chromosomes each in the sperm and egg. After the male and female donkeys mate, the sperm and egg will also combine, returning to 62 chromosomes.

And when a horse and donkey crossbreed, the sperm and egg are 32 chromosomes and 31 chromosomes respectively, and the final mule is 63 chromosomes. And mules want to have offspring and let their germ cells meiosis. But the question arises, the process of meiosis, the number of chromosomes will be halved, 63 chromosomes how to halve?

After all, there are no 31.5 chromosomes, so it is difficult for a mule to produce sperm and eggs that have reproductive efficiency, and there is no way to revert to a 63 chromosome state. It is because of the inability to undergo efficient meiosis that mules are very difficult to achieve reproduction on their own. Therefore, there is no point in dividing mules into males and females.

Conclusion

The reason why rural people say "mules don't distinguish between male and female" is because, during the long-term breeding process, they found that mules can hardly produce offspring and there is no point in distinguishing between male and female. The main reason why a mule cannot produce offspring is that it is a cross between a horse and a donkey and has a single chromosome, so there is no way for effective meiosis to produce sperm and eggs. Therefore, the mule itself cannot be considered a separate species.