Animals in nature know how to mate. Who taught it?
The result of mating is reproduction, and animals understand it, indicating that this matter is very important, it is important that it does not allow you to learn the day after tomorrow, and is directly printed in the genes. Let ’s talk about its importance and how this behavior is writtenInto the gene becomes instinct.
To understand the origin of mating, we must first understand the logical order of natural selection, which is very important :
All the characteristics of living things are generated by living things independently. They are not taught or imposed on us by the external environment. The natural environment will not help us to set wings and teach us how to breathe. There are so many types of living things today.Different characteristics are the result of our own efforts.
When the earth was first formed, there was no oxygen, and most of the organisms were anaerobic. More than 600 million years ago, cyanobacteria appeared and oxygen was produced through photosynthesis. These anaerobic organisms became extinct, and only a small part of them were produced.The organisms that adapt to the oxygen survive the mutation. A small part of the mutation is randomly generated by the organism, not the natural church.
From here we can see that the formation of the mutation was before survival. It was ABCDEFG ... these options, and then naturally began to ask questions. Instead of the survival problem, everyone began to answer for survival, and began toIt's a misunderstanding to adapt to the environment to change.
Find out the order, we look back at mating. We all know that living things are divided into sexual reproduction and asexual reproduction.
A kind of asexual breeding organism belongs to anaerobic type, so its descendants are anaerobic type. Asexual reproduction gene change can only rely on gene mutation, and the probability of gene mutation is extremely low.
Example: Living body AB, after a period of reproduction, the offspring are all genes are AB. After a large number of reproductions, mutation A 'appears, so this mutation A'B begins to breed its offspring, life body A'B.Now there are life forms A'B and life form AB, which continue to reproduce, and after a period of time, life form AB, and mutation B 'appears again, so there are AB, A'B, AB'.
This method reproduces very quickly. It is very simple. It keeps copying itself and splitting itself. As long as the environment is suitable and the energy source is sufficient, it can be copied all the time.
The advantage of sexual reproduction lies in the exchange of genes, and gene mutations can spread.
still the example just now:
Two kinds of life forms, they have chromosomes AA 'and BB' respectively, only need to mate, and the offspring will appear AB, AB ', A'B, A'B'. A small number of life forms can appear very manyGene combination. There is diversity in sexually reproduced genes, and there has been no analysis of gene mutations. When an individual's gene is mutated, the mutation can be passed to N next generations through mating, and the next generation will be transmitted through mating.To N later generations. As time goes by, as long as this mutation is beneficial and harmless, it can be passed on for a long time.
If the earth is a laboratory, asexual reproduction is constantly increasing its number. Sexual reproduction is to provide enough "trial and error" samples for the experiment, and each sample is not the same.
Going back to the beginning, the above mentioned is the emergence of options first, and then the natural screening problem. From our analysis of reproduction, it seems that the diversity of sexual reproduction has greater advantages in the face of natural selection. In other wordsIt is said that natural selection preserves a large number of sexually reproduced organisms. The genes of the mating organisms have DNA corresponding to mating, so when the organisms were formed, they contained mating characteristics.
Who is the church?
We all know that the earliest organisms after the birth of the earth were asexually reproduced. So how did sexual reproduction occur? In the current discovery, sexual reproduction began 0 billion years ago, and it was first discovered in the central Australian plant.The spore fossils produced by several divisions. Although scientists found the spores, they could not explain how sexual reproduction originated.
Although there are no accurate results now, but gene mutation cannot be avoided. Due to the genetic mutation, a vegetatively reproduced cell keeps replicating only half of the DNA because of the gene mutation. When encountering another cell with the same situation, twoThese cells combined to produce a new cell, which inherited the characteristics of meiosis and passed on from generation to generation.
Or another cell ate another cell and found the DNA of the other cell during reproduction. To save trouble, it only copied half of its own genes, and took the other half of the other hand to cultivate a new cell.
Because of various reasons, this new method is more suitable for the changing earth, so it is retained to this day.
This article is uploaded and published by the media, authors, etc. in Baidu Know Daily. It only represents the author ’s point of view, and does not mean that Baidu knows the opinion or position of the daily newspaper. It is known that the daily newspaper only provides an information publishing platform. For cooperation and contributions, please contact email@example.com.