We know that the current is very low, so fish must not reach the heights. There are fish in some swimming pools on high mountains. Probably because some fish eggs got in. The principle is like insects, similar to pollination. The behavior ability of plants is not as good as that of fish, but its species can spread all over the world. Maybe it's because some animals don't digest eggs after eating them, and then they are excreted with feces. Where there is water on the mountain, it has been hatched, so the trust in nature is absolutely unconvincing.
There may be no fish in the pond itself, but it may appear because of the parade of fish. In addition, there may be external forces. For example, after other creatures kill fertilized fish, they come to the pool and unconsciously excrete undigested fish eggs, so that these fish can exist. However, it is also possible that someone deliberately puts eggs into the pond, provided that the temperature and oxygen in the pond are very suitable for fish to survive. The water quality is also suitable for the growth of fish eggs. This situation has already appeared in some villages. Many people want to try their luck and solve the problem of food and clothing.
For the world we live in now, it is a myth to want to hatch a life. However, if you do this through some turnover or other high-tech technologies, you may be able to realize our imagination. This is a coincidence of nature's karma, but it is not formed by biological evolution step by step. After all, that process is too slow, and it usually takes hundreds of millions of years until that happens.
up to now, all we have to do is try our best to create a living environment suitable for life. Then consider whether we can increase life and obtain different species, but for now, the most urgent task for mankind should be to protect the earth.