gene transmission is hidden very profoundly. In nature, no animal can know this. We humans only understood the rules of genetic combinations in the last century, thanks to Mendel .
Before, due to the lack of scientific knowledge, humans sometimes broke through the shackles of morality to intermarry in close relatives, which left a painful lesson in the European royal family.
The most typical example is the 16th-century Spanish Habsburg dynasty . In order to ensure that the throne is rotated, they always get to power, so they seek the ultimate purity of family traditions;
As a result, genetic diseases are infinitely amplified in generations, and in the end the entire dynasty only experienced the extinction of the only male child infertility.
This is the biggest lesson of inbreeding. It will not make offspring better, but will make hidden harmful genes more and more pure, which will eventually lead to offspring suffering from serious genetic diseases and even infertility.
If an animal species always maintains inbreeding, or cannot avoid inbreeding correctly and effectively, then the entire population will be at a threat.
However, this phenomenon of inbreeding is generally most likely to occur in sociable animals, and the "Lone Ranger" does not have such troubles, which is easy to understand;
Because the group animals are mixed, all kinds of relatives live together, and males have the ability to reproduce no matter which age group, the young female offspring in the group will gradually mature;
In addition, the group animals do not have moral constraints and do not understand the laws of genetics, so animals with group and social nature must find ways to avoid the risks of inbreeding.
. An animal that is lonely will not see the appearance of his father after birth, and will immediately leave his mother's care and disperse it into nature after growing up. Therefore, there is no risk of close relatives, which can be said to be quite low.
Humans are obviously group mammals, but the advantage of humans is that they have social and moral constraints. However, in ancient times, they also broke through this constraint due to the lack of scientific knowledge. For example, the example given in the above, but it is a rare situation after all.
Moreover, in human history, the number of groups and populations has been huge since ancient times, so it can also avoid the risk of close relatives well.
Other societies need to think of other ways to avoid them. Below I will introduce two societies: lion and lion-tailed baboon to see how they are done.
African lion is a typical large-scale carnivore in a group. There are often 20 lions in a group, but most of them are female lions and young lions, and 1 to 3 male lions.
Among the lions, one of them is the lion king, which leads the entire group and protects the territory. The lion king has absolute leadership and mating rights in the group. During the breeding period, the females in the lion group will mate more with the lion king, but will also mate with other male lions.
However, other lions will not stay in a group of lions for a long time, because as a lion, they are born with the desire to be the eldest brother. They will run away from home and find their own home, and some lions will even be driven out by the lion king.
The next problem is that if the lion king stays in the group, the male lion will be at risk of mate with its female offspring, and when the male pups grow up, they will be at risk of raising offspring with their own parent females, or their own parent generation. How to avoid
? One of the male and female must leave, who should she leave? It must be males. When the male cubs grow up, they will be driven out of the lion group. They need to go out and break into their own world. They need to be lion kings.
These young males who walked out, as well as the males who had been temporarily staying in the lion group, will go to various lion groups to challenge their lion king. The old Lion King will also be driven away after being defeated by the younger generation.
So in the lion group on the African grasslands, males will rotate constantly, and the lion kings will often be defeated and driven away by the younger generation. Therefore, such rotation can avoid the risks of close relatives in the lion group.
There is a more interesting thing here. Although male lions are born to want to be lion kings, not every lion can become lion kings. In addition, the number of lion groups on the grassland cannot make all male lions become lion kings.
Therefore, on the grassland, you often see a group of male lions, including the new young generation, the elderly, the newly defeated lion king, and the middle-aged generation who are depressed and unsuccessful. They have no home, so they spontaneously walked together to form a team called the Men's Gang. They are all good buddies, and this group has an extremely powerful combat power.
Among them, the elderly lions are in this group until they grow old. The middle-aged generation may challenge other lion kings again. If they win, they will reach the peak of their lives. If they fail, they will return to the Men's Gang. The same goes for the younger generation. They will definitely challenge other lion kings.
This is how lions turn their males, and it is also how they avoid close relatives.
Next, let’s talk about lion-tailed baboon. The name shows that it is an baboon , and it is also a social animal. Researchers have observed their groups for 14 years and discovered something particularly interesting and magical.
and published a paper in the journal Contemporary Biology, which revealed how lion-tailed baboons avoid close relatives.
Researchers found that female lion-tailed baboons have the ability to control their sexual maturity, that is, these females can actively slow down or speed up their maturity period. To prevent inbreeding with male lion-tailed baboon kings in the group.
The lion-tailed baboon group is the same as the African lion group. There is a king. The king must have absolute mating rights. After the male cub matures, he will take the initiative to leave the group, which is like a lion.
However, when no other foreign males enter the group, they will suppress their maturity without the foreign males defeating and replacing the current Lion-tailed Baboon King.
When foreign males appear in the group, scientists found that female lion-tailed baboons in the group will produce a large amount of hormones in a short period of time, which can speed up their rapid maturation.
The most obvious manifestation of mature females is that the red part in the front of the body becomes larger. But scientists don't know how they do this and can actually control their own development.
or above are two typical methods of social creatures to avoid inbreeding, but it is undeniable that all social animals use these methods to avoid inbreeding;
, but a small number of close relatives are harmless to the entire population. Because we humans now use inbreeding, that is, backcrossing, specifically to allow some animals to reproduce with their parents and strengthen certain excellent shapes.
