Thesa. The appearance of the first diploid unicellular animals, close to the modern ones, occurred through the elongation of the stage of a double chromosome set from the process of reproduction of primary spermatozoa.
   Later, at one of the stages, it became possible to multiply an animal cell (i.e., a spermoid) by doubling the number of chromosomes (already already there were two) and then dividing into two new cells. This division is called mitosis. Thus, both meiosis and mitosis arose at the stage of unicellular organisms. The first meiosis appeared and it was preserved forever, because it created high adaptive possibilities. Mitosis simply serves as a breeding without variation of the genotype (except for crossing).
   There is a well-known dispute between different schools of biologists. According to some, evolutionary change begins when the population falls into unaccustomed conditions of existence. New external factors act directly on the ontogenesis of individuals and cause morphoses. Morphoses represent a new material for natural selection. If any of the newly appeared morphoses is able to exist under changed conditions, then natural selection leads to genetic assimilation of this morphosis. Thus, evolution begins with a change in the environment and ends in the genome. Other scientists, followers of Darwin, view evolution as the reverse sequence of events: from a new gene to a new ecosystem.
   It seems, and we think so, that in the light of the above, both are right. The chromosome that lives inside the cell, although protected from the influence of the external environment, but not 100%. That is, a small reverse effect of the external environment on it necessarily exists. Therefore, on the one hand, random mutations of the chromosome itself can be fixed if they are successful. But on the other hand, changes outside create tension inside the cell, which sometimes leads to the fact that: a) the cell weakens and becomes uncompetitive b) to the forced mutation of the chromosome in the direction of removing the external voltage. c) the competitiveness of such an accidentally mutated chromosome, which previously was consistently uncompetitive.
   Recall the law of physics: every system that is under external influence behaves in such a way as to reduce this impact. Summary: evolution is possible even under unchanging external conditions. The only driver of this evolution is random mutations, although they can give out very progressive changes. The consolidation of such mutations in the ecosystem depends on the response of other members of the ecosystem. Not every, even progressive mutation is able to gain a foothold, if in parallel there are no suitable mutations of contacting species. But when the external conditions change, the intensity of the mutations increases and their direction is determined by the change in external conditions.
   You can also recall our long-standing reflections that there are no stable states in Nature. The ecological niches are being filled. Nobody knows the size and shape of these niches.
   Yes there is biology. That brightened in the head of a man (A.Parshin - "Why is not Russia America?") And he realized that all the troubles in Russia are coming from the climate. Truly so! And what do you want to do with your favorite writers who have covered the Russian reality? After all, these writers are wrong! Gogol, Chekhov - they are wrong! After all, like in India or Africa: jumped, ripped off a banana and you are full. And we have to work half a day to feed ourselves. They hung a rag or leaves on their hips, and you're dressed. And we - work in the second half of the day for clothes. In Europe, I built something, a building, a road, a bridge - and it costs 100 years. And we have after the winter - a mandatory repair of everything. More than three years without repair in our climate, no structure can withstand! And favorite writers laugh. And the humorists roll off, why are we so clever, and so poor? And we do not understand, and humorists do not understand. But the man understood and we all became fools. So in biology: how many theories seemed correct, intelligent, ingenious. And look wider - and complete nonsense. Well, what natural selection? Well, they eat sick, old and defective. And everything else is very doubtful.
   Gradually, oxygen accumulated in the atmosphere. In the oxygen atmosphere, all the processes went much more actively and very complex molecular formations and multicellular organisms became possible.
 

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