Lead:
The word isolation scares many people, and how terrible is reproductive isolation, simply put, reproductive isolation refers to a force that causes individuals to not be able to interbreed in a group.
So what are the main functions of reproductive isolation and how is it formed?
Today, I will introduce you to this knowledge.
So how does reproductive isolation come about?
1. The role of reproductive isolation.
1. Reduce hybridization.
The main role of reproductive isolation is to limit the interbreeding between individuals, so as to reduce the opportunity of interbreeding between individuals of different species, so as to maintain the purity of the species, if the individuals between different species interbreed, then the hybrid individuals may also be a new species, and most of this new species are not conducive to the survival of the group, and even some species will produce offspring that cannot reproduce because of hybridization, which will lead to the number of groups becoming smaller and smaller, and finally gradually disappear on the earth.
Therefore, reproductive isolation plays a very important role in this context.
2. Differentiation organisms.
Reproductive isolation can promote the differentiation of organisms to a certain extent, and over thousands of years, under the influence of different habitat environments, individuals of the same species will gradually produce small differences, and over time, this small difference will evolve into large differences, and eventually different species may be formed.
Reproductive isolation is the population isolation that restricts the production of offspring between individuals of different species, and this isolation can obviously promote the differentiation of species.
3. Maintain species stability.
Reproductive isolation also maintains the stability of the species, as there are fewer opportunities for crossbreeding between different populations, so that new populations do not appear frequently and the numbers of different species are not affected too much.
2. The formation of reproductive isolation.
1. Species mutations.
Mutation of species is an important reason for the formation of reproductive isolation, and the mutated individual has a different reproductive organ from the original individual, so that a new reproductively isolated individual can be formed.
Isolated individuals are unable to produce offspring with individuals of the same species, which gradually leads to reproductive isolation.
Over the course of evolution, taxa all go through a continuous stream of variations, some of which may be temporary and disappear in one generation, while others may stabilize and remain in future generations and eventually become a permanent genotype.
When a genotype changes to the point where it is impossible to produce offspring with individuals of the same species, this can produce reproductively isolated individuals, and thus gradually form reproductive isolation.
2. Space isolation.
Spatial isolation is also one of the reasons for reproductive isolation, some species live in the same area, but the ecological environment in which they grow is very different, and spatial isolation is the behavior of reproductive isolation of individual species under the influence of these ecological environments.
In spatially isolated species, the difference in the ecological environment will also cause the difference in the ecological environment of different individuals, which will lead to the fact that individuals are very selective when looking for mating partners, so that there will be no chance of mating between individuals at all, so that reproductive isolation will occur.
3. Behavioral isolation.
Behavioral isolation is very common in reproductive isolation, and many species reproduce through behavior, and this behavioral reproduction habit adapts to different geographical environments, so that different populations will be formed, resulting in reproductive isolation.
3. Classification of reproductive isolation.
1. Pre-mating isolation.
Pre-mating isolation is generally isolated before mating, and pre-mating isolation is mainly due to the fact that the external traits or living habits of individuals are very different, which makes it difficult to identify whether the other party is of the same species during mating, so the direct result is that there is no chance of mating at all.
2. Post-mating isolation.
After mating, the isolation is the reason why individuals of the same species cannot produce offspring after mating, mainly due to the differences in individual life stages, which leads to the fact that mated individuals rarely produce normal offspring.
3. Combined isolation.
Combined isolation means that although mating can produce offspring, due to the different physiological mechanisms between different individuals, the number of offspring is very small, and ultimately reproductive isolation is formed.
4. Reproductive isolation between plants.
There are thousands of reproductive isolation between plants, and some of them are naturally reproductive isolated, such as vegetables, fruits, and grains.
In order to maintain the purity of the varieties, these plants often use artificial methods to separate the different varieties, thus reducing the chance of hybridization between these plants.
The reproductive isolation of bamboo plants is that when bamboo reproduces, seeds are generally produced through flowering, and the bamboo of bamboo plants grows from the ground and will only bloom once, and the time and place of flowering are not the same, so as to avoid the phenomenon of reproductive isolation between bamboos.
However, some plants do not have natural reproductive isolation, but the growth environment and living habits can affect the opportunity of hybridization between individuals, which is similar to conditional isolation, which is a relatively common reproductive isolation phenomenon, such as the reproductive isolation of plants in mangrove forests is because of the humid environment, resulting in many plants relying on aerial roots to grow, which will make it difficult to exchange seeds between plants, so as to avoid the phenomenon of hybridization between species.
5. Examples of reproductive isolation in humans.
In humans, the phenomenon of reproductive isolation is also very common, but reproductive isolation in humans is mainly reflected in the ecological environment of human beings, and one of the more famous habits is lowland race and highland race.
The lowland race generally lives at a lower altitude, so its body shape will be shorter than that of the highland race, while the highland race lives in a higher place, so that the body shape will be taller.
Moreover, the lungs of lowland people will be stronger, because the hypoxia phenomenon is more severe at higher altitudes, while highland people are better at endurance sports, and this difference in ecological environment makes it almost impossible for different groups of people to interbreed, so this is a form of reproductive isolation.
In fact, reproductive isolation is also very common in human beings, it can be said that reproductive isolation is a product of human evolution, and most reproductive isolation is suitable for the human ecological environment.
For example, reproductive isolation is also reflected in the ecological environment, living habits, and appearance between different races, which makes the opportunity for interbreeding between different races very small, so this is a form of reproductive segregation.
Epilogue:
Reproductive isolation is not only in animals and plants, but also in humans, and the existence of this reproductive isolation can also promote the differentiation of species, reduce hybridization, and maintain species stability to a certain extent.