Globalization Today, the earth has become a small "village", and it is very common for people of all skin colors to intermarry with each other.
Love between yellow and black people
It is strange that people of different skin colors have certain differences in body shape characteristics and bodies, but why can black, yellow and white people mate? Doesn’t reproductive isolation exist among humans?
What is reproductive isolation
The so-called reproductive isolation is actually in nature. The race of with kinship cannot mating . Even if offspring is given birth, offspring cannot reproduce.
So, what is a race with kinship?
Mules do not have fertility
Generally speaking, there is a common ancestor between the two races . Because it is split in the long-term evolution process, it has certain similarities in genes or appearance characteristics.
For example, humans and chimpanzees have such a relationship . 4 million years ago, humans separated from the group of chimpanzees for the first time. After three independent evolutions, they finally became a new species.
During the genetic evolution process, due to the changes in chromosome arrangement, reproductive isolation between humans and chimpanzees appeared.
chromosomal differences between humans and orangutans
In the last century, a biologist tried to use humans and chimpanzees to reproduce their offspring, and ended in failure. The biologist was also imprisoned for his cruel experiments.
It can be seen that reproductive isolation is a red line of that cannot be crossed by in nature. Even humans who claim to have conquered nature cannot break through its shackles. The conditions for reproductive isolation to occur are very simple. As long as the time is separated by is long enough, reproductive isolation will naturally occur. This phenomenon will also occur on the same species.
Reproductive isolation cannot transcend
Reproductive isolation is common among animal groups. For example, Mule is a hybrid breed born by donkeys and horses by chance.
lion and tiger beast and tiger lion beast in the zoo are breeds that were bred after lions and tigers. Due to the different mothers of fertilization, there are also obvious differences in the characteristics of offspring.
What is strange is that has such obvious differences in humans scattered across continents , why is there no reproductive isolation in humans?
People of different races do not have reproductive isolation
racial differences are small
Although there seem to be huge differences between different races, biologists have found in the study of human genes that no matter what race it is, there are only slight differences in genes . This subtle difference in
is not even enough to be the standard for dividing humans.
In biology, according to the distance of kinship, defines the division criteria as "domain, boundary, zodiac, class, order, family, genus, and species."
starts from the first one, and the closer the kinship relationship to which it belongs is, the closer it is. No matter what kind of human it is, it belongs to the closest "species" category.
Species division
In the "species" category, it cannot even differentiate subspecies , which shows the intimacy of human relationships.
So how do so-called people with different skin colors appear?
This goes back to a modern sociologist . In order to facilitate research, people were classified in a unified way in terms of skin color. The standard
has been changing and has developed to this day, which is the well-known three types of , yellow, black, and white.
It is worth mentioning that the division of skin color also contains the bias of white people .
divided by skin color
In Western culture, black represents devil, yellow represents timid and cowardly, and white represents elegance and purity. Westerners give themselves beautiful meanings, and bad meanings to others, which is disgusting.
In fact, as long as people pay attention to it, they will find that the skin color of yellow people is actually not yellow , and many girls have whiter skin than Westerners.
Since the title contains prejudice, why do Chinese people still happily accept it?
Because for Chinese culture, yellow represents dignity and authority. In the eyes of Chinese people, the title of yellow people is actually praising themselves.
Chinese people respect yellow
Is it a prejudice or praise? I personally prefer the latter. How many years has Western culture been? With a 5,000-year civilization in Chinese culture, Chinese people must have cultural confidence and cannot be led by Western culture.
Back to the topic, it seems that skin color cannot be a reason for reproductive isolation .
The reason for the difference in skin color in humans is also very simple. Black people living in Africa receive light all year round, so there is naturally more melanin in their skin.
. Westerners living in high latitudes obviously do not have enough light in terms of light and appear pathological white. overall, the skin color of yellow people is the healthiest.
Yellow people are healthier
shorter isolation time
According to archaeologists' research on human fossil , exploring the origin of human beings, all the evidence points to one place, that is Africa.
Millions of years ago, Africa was still a forest, with a warm and humid climate there, and ample food and is very suitable for animals to live in .
After humans differentiated from orangutans, they have been undergoing further evolution in Africa.
From Homo erectus to sapiens , the ancestors spent more than 3 million years and finally became an independent branch.
During the evolution process, the geographical environment of Africa has also changed one after another, and has become no longer suitable for human habitation from a superior environment.
Africa is no longer suitable for human habitation
A variety of Natural disasters occur frequently, making water sources and food scarce, and the ancestors of human beings have successively emerged from Africa.
About 200,000 years ago, Homo sapiens walked out of Africa. Unfortunately, these Homo sapiens did not reproduce and soon became extinct in various continents. After
, Homo sapiens walked out of Africa, and stepped through various continents outside Antarctica , thriving in their respective territories, and nurturing humans from primitive tribes.
From the timeline, the time when humans on various continents are truly isolated is only ,000 years of history, and no more than 200,000 years at most.
Human ancestors walked out of Africa
If you want to have reproductive isolation, you must at least have a million years. In terms of time, humans are not satisfied.
What's more, since the birth of human civilization, humans have been communicating on , such as the recorded Xuanzang traveling west, Marco Polo traveling around the world, etc. There are many examples of human communication.
If you include those adventurers who cannot be recorded in books, you will have to double it a few times.
, especially after , the age of navigation , human interactions on earth became more frequent, and , the races from various continents were integrated into .
Great voyage connects the world
In today's information age, it is no exaggeration to say that the earth is a "village". As long as the network is smooth enough, instant conversations with friends on the other side of the earth can be easily achieved.
Generally speaking, no matter what skin color, people will not be able to have reproductive isolation , and humans can reproduce freely.
After understanding human reproductive isolation, some people will be curious about what reproductive isolation of in nature is like.
Reproductive isolation in nature
In the study of biologists, reproductive isolation in nature is divided into many types.
There are different reproductive isolations in nature
First, geographically reproductive isolation of refers to the isolation phenomenon that caused the two species to be unable to communicate due to geographical segmentation during the evolutionary process.
For example, during the period of plate differentiation, animals with relatives in are separated from each other, and reproductive isolation occurs over time.
Second, seasonal reproductive isolation, this phenomenon mostly occurs in plants. For example, between the same plants, blooms and pollinates in different seasons, and cannot get "communication", so naturally evolved into a distant relationship.
Flowers of different seasons are different
3rd, Ecological environment isolation, species of animals have different living habits in different environments, and they will evolve towards the environment in which they are used to living. During the formation process of
, the ovulation period of female organisms begins to show differences.
Because in order to ensure that their offspring have a higher survival rate and have a better fertility environment, female animals place their ovulation period in a suitable period of survival.
So, genetic changes began to be made, and reproductive isolation gradually appeared.
In short, there are many types of reproductive isolation in the animal world. As long as relatives can communicate for a long time, reproductive isolation can occur.
Reproductive isolation is to allow genes to be better continued
Reproductive isolation organisms mated, and the offspring produced are almost impossible to develop into embryos. If they develop for a long time, some genes will be lost during the binding process, leads to the decline of species genes .
Compared with animals in nature, humans are extremely close, so I hope everyone will let go of their prejudice and truly achieve equality for everyone.
