What causes the reproductive isolation of animals, and what is the reproductive isolation between an

The two do not belong to the same species, and reproductive isolation occurs after mating.

Many animals can be cross-bred, why are humans "reproductively isolated" and can have children with orangutans?

It is a protective mechanism that not only maintains the stability of genes, but also keeps the balance of individual populations from being disturbed. Reproductive isolation refers to the isolation mechanism that makes groups that are closely related to each other not mate under natural conditions due to various reasons, or even if they mate, they cannot produce offspring or cannot produce fertile offspring.

Formation of reproductive isolationThe first step in the formation of reproductive isolation is usually geographical isolation, where different populations of the same species are separated due to climatic and topographic changes, and are separated from each other by an insurmountable geographical barrier. Each of them undergoes non-directional mutations, but only individuals who adapt to their environment can survive. Natural selection pushes them in different directions, and over time their genetic and morphological differences become more and more significant, until they become reproductively isolated from each other.

In addition to geographical isolation, the external causes of reproductive isolation include ecological isolation, behavioral isolation, seasonal isolation, etc., and the final result is either the inability to complete the mating action, the incompatibility of gametes, or the failure or decay of the hybrid, and the infertility of the offspring, so that reproductive isolation is formed.

Reproductive isolation is an evolutionary mechanism that is essential for speciation to prevent interbreeding between members of different species to produce offspring, maintaining species integrity by reducing gene flow between related species. In order for different species to separate from their common ancestors and advance evolution, reproductive isolation must occur. There are several types of reproductive isolation that lead to speciation, one of the most common is prezygotic isolation before fertilization between gametes, which prevents sexual reproduction of different species, but there are also mechanisms of postzygotic isolation.

Basically, if individuals cannot reproduce with each other, they are considered to be different species, so different breeds of dogs can cross with each other to produce fertile offspring, so different breeds of dogs are all the same species, even if the morphology is very different. Theoretically, there is reproductive isolation between any different species.

For example, in snails and snails, the direction of the spiral on the shell is generally specific to the species, and the chirality of the snail (left-handed or right-handed) is determined by a single gene.

In the process of evolution, animals may reach the same destination through different evolutionary paths, and eventually evolve similar structures or characteristics to solve similar purposes or use certain resources, and these striking similarities are known as convergent evolution. Mammals, for example, marsupial echidna and hedgehog, both independently evolved stinging hair as a form of defense, but the two diverged more than 100 million years ago.

Similarly, the Tasmanian tiger (thylacine) is virtually indistinguishable from modern canines, but the Tasmanian tiger is more closely related to the echidna than the dog. Similarly, although they look like rats, quolls are very evolutionarily related to rats.

The advent of reproductive isolation means the emergence of new species. Even if the animals are not of the same species, it is not surprising that there is reproductive isolation. However, there may be "gray areas" or "transition zones" in the process of evolution, in which the species does not completely become a new species.

Although they are very similar, they are not the same species, and the number of chromosomes may not be the same, and the genes are not the same, so there will be reproductive isolation.

Because these animals are only similar in appearance, their genetic characteristics are completely different, so there is reproductive isolation.

This is because the body structure of each animal is different, so there is some reproductive isolation.

It's because there are many similarities in the body structure and the genes in it, and if you choose to reproduce, it is likely to bring harm.

There are some similar animals in nature that are reproductively isolated, although tigers and lions are at the top of the biological chain, but they can not reproduce with each other, even if they reproduce offspring, they cannot continue to reproduce, just like human beings will not produce offspring with ordinary creatures, this is the law of nature.

Some very similar animals are reproductively isolated because their gene pools, although similar, are so different that they cannot naturally mate with each other or produce fertile offspring.

This is because the body structure of each animal is different, and some animals are reproductively isolated.

There is reproductive isolation between humans and animals, why not between different races?

The so-called reproductive isolation is the inability to produce offspring or the infertility of the offspring produced by the union. Therefore, strictly speaking, it can be said that as long as there is reproductive isolation, it is a different species.

There is no reproductive isolation between dogs and wolves! Dogs such as German Huskies can cross with wolves and give birth to fertile offspring.

For various reasons, the isolation mechanism that makes groups with close kinship not mate under natural conditions, and even if they can mate, they cannot produce offspring or cannot produce fertile offspring, which is called reproductive isolation. And as long as there is no reproductive isolation, it is the same species, so there must be reproductive isolation between different species.

There is not necessarily reproductive isolation between different populations, it may only be geographical isolation, but because the time is not too long, such as the South China tiger and the Siberian tiger, they still belong to the same species, and the concept of population is only all individuals of the same species that occupy a certain space for a certain period of time. But a species can have many populations, so not necessarily, after all, a species is distributed in different places and is also different populations

You just need to remember that as long as there is reproductive isolation, it must not be the same species, and even if it gives birth to offspring, it is also sterile, such as the birth of a donkey. And with only geographical isolation, not necessarily.

Not necessarily, anyway, some of the reptiles and amphibians that I have identified are still fertile in their offspring from different species of the same genus.