What is Reproductive Isolation? How is reproductive isolation formed?

Reproductive isolation refers to the fact that some groups of species cannot mate under natural conditions, and even mating cannot produce offspring or give birth to offspring. Reproductive isolation is a phenomenon that occurs when factors in nature are repeated and lead to isolation.

Reproductive isolation is a management mechanism that separates some close relatives or is unable to reproduce excellent offspring; Reproductive isolation is based on the evolution of a long period of time, and the emergence of some genetic mutations, chromosomal mutations.

Reproductive isolation means that kinship does not mate under natural conditions. It is also possible to have a mechanism that does not produce offspring. Reproductive isolation is formed due to the repetition of factors in nature that act as isolation.

Reproductive isolation is due to various reasons, which are caused by the fact that groups of closely related relatives do not mate under natural conditions, and are formed by the evolution of species, which is caused by different evolutionary forces.

Let's take a look at what reproductive isolation is:

Reproductive isolation refers to the isolation mechanism that makes the groups with close kinship not mate under natural conditions due to various reasons, or even if they can mate, they cannot produce offspring or can not produce fertile offspring, and if the isolation occurs before fertilization, it is called reproductive isolation before fertilization.

To put it simply, there can be no breeding between different species, and even if they are mated, there will be no offspring.

In general, there is reproductive isolation between organisms, which is mainly related to the following aspects:

1) Geographic isolation.

It is because of the geographical location that the two species cannot reproduce. For example, if one lives in the North Pole and the other lives in the South Pole for a long time, and due to their geographical location, the two cannot meet at all, so they cannot mate.

For another example, if one flies in the sky and the other climbs on the ground, the two do not intersect, and they cannot mate.

2) Isolation between different species.

Some animals have different ways of reproduction due to different species, for example, the fertilization of fish is completely different from that of birds, and even if they are put together, there will be no intersection, let alone new species.

3) In vitro isolation.

Every animal has its paired DNA, that is, chromosomes, that is, it can be mated, because the chromosomes are not paired, it cannot be fertilized normally, and it is impossible to produce a new generation.

The significance of biological isolation: the above types of reproductive isolation are essentially hindering the gene exchange between different species, so that each isolated population has strong stability, so as to ensure the development of each according to the direction adapted to the environment under natural conditions. Thus, species are populations of reproductive isolation, and the progression from geographic isolation to reproductive isolation is a fundamental factor in the formation of most species.

In fact, it is an obstacle that there is no way for different species to reproduce offspring, and reproductive isolation is actually a self-selection in terms of genes, and there is no way to intervene.

It's because of blood relations, so there is no way to mate, if there is a desire to defecate after mating, which has a lot to do with blood, so it can't be cleaned, and because of geography, it can't reproduce between two species.

1. The essence is different.

Geographical isolation is due to geographical factors that divide a species into two different geographical regions.

Reproductive isolation refers to the isolation mechanism that makes groups with close kinship not mate under natural conditions due to various reasons, and even if they can mate, they cannot produce offspring or cannot produce fertile offspring.

2. The scope of inclusion is different.

The genes of two geographically isolated species can no longer communicate, and it is possible that prolonged geographic isolation will eventually lead to reproductive isolation, and the species in the two regions will become two new species.

reproductive isolation before fertilization, including geographical isolation, ecological isolation, seasonal isolation, physiological isolation, morphological isolation, and behavioral isolation;

Reproductive isolation after fertilization, including hybrid inactivity, hybrid sterility and hybrid decay, etc., for example, donkeys and horses are two species, even if they can mate and give birth to mules, but in a general sense, mules are generally considered to be no longer able to mate with each other and directly give birth to offspring.

1. Due to reproductive reasons, groups with similar kinship do not interbreed, or hybridize sterile, or produce sterile offspring after hybridization.

2. The essence is that individuals in different populations have different reproductive behaviors and related reproductive rates due to the control of different genotypes, so the flow of cave silver genes between populations is restricted or hindered and cautiously stopped.

3. The reproductive isolation between species is maintained by different reproductive isolation mechanisms, which prevent the flow of genes between species, which is a biological characteristic that prevents interspecific hybridization. According to the main period of isolation, the reproductive isolation mechanism is divided into two categories: reproductive isolation before fertilization and reproductive isolation after fertilization.

If the isolation occurs before fertilization, it is called reproductive isolation before fertilization, which includes geographical isolation, ecological isolation, seasonal isolation, physiological isolation, morphological isolation and behavioral isolation; If isolation occurs after fertilization, it is called reproductive isolation after fertilization, which includes hybrid inactivity, hybrid sterility, and hybrid fibrillation and decay.

Reproductive isolation refers to the isolation mechanism that makes the groups with close kinship not mate under natural conditions due to various reasons, or even if they can mate, they cannot produce offspring or can not produce fertile offspring, and if the isolation occurs before fertilization, it is called reproductive isolation before fertilization.

Population:

A population is the smallest ecological unit studied in ecology. A population refers to a group of individuals of the same species who are distributed in the same ecological environment and can freely mate and reproduce. In the hierarchy of biological tissues, the population represents the first level from the individual level to the population level.

Because sexual reproduction is a process of genetic recombination, which produces new variations that are available for natural selection, populations that mate with each other constitute an evolutionary unit that may be the starting point for the differentiation of new species.

Some organisms also form a certain community structure around the reproductive relationship. On the other hand, individuals in the same area share the same resources, so there is intraspecific competition or cooperation in the relationship between resources.

Geographic isolation can result in reproductive isolation.

1. Geographical isolation of limbs: The same organism is divided into different populations due to geographical barriers, so that gene exchange between populations cannot occur. Groups live in different habitats and cannot meet each other.

For example, oceans, large landmasses, mountains and deserts hinder the free migration, mating, and gene exchange of organisms, and finally form independent populations. Geographical isolation leads to reproductive isolation, and different species cannot mate with each other. And according to the specific geographical environment, it gradually evolves in different directions.

This is a key factor in the formation of species diversity.

The way it affects the evolution of species is as follows: geographical isolation—different natural selection—different evolutionary directions—differences—reproductive isolation—new species.

2. Reproductive isolation: under certain geographical conditions, the same species produces geographical isolation in different geographical environments. After a long period of geographical isolation, they change from each other, resulting in reproductive isolation.

After the birth of reproductive isolation, it is transformed from the same species to two species! It's called reproductive isolation!

However, in real life, reproductive isolation does not necessarily have to be geographically isolated. For example, the cultivation process of seedless watermelons.