What are the advantages and disadvantages of biological variation?

For an organism, some mutations are beneficial to its survival, which is called favorable mutation. For example, dwarf and lodging-resistant variation in wheat are favorable variations. Some mutations are not conducive to its survival, which is called reverse mutation. For example, corn sometimes has albino seedlings. Such seedlings have no chlorophyll, can not carry out photosynthesis, and will die prematurely, which is an unfavorable mutation.

Significance of variation in biological evolution

In the process of reproduction, organisms constantly produce various favorable variations, which is of great significance to the evolution of organisms.

The environment on the earth is complex, diverse and constantly changing. If organisms can't mutate, they can't adapt to the changing environment.

If there is no genetic variation, there will be no new biological types, and it is impossible for organisms to go from simple to complex, from low to high.

Constantly evolving. It can be seen that variation provides original materials for biological evolution.

The application of variation in agricultural production in crops, poultry and livestock sometimes has beneficial variation. For example, there may be cows with better meat quality or cows with more milk. People choose this kind of cattle to breed in large quantities, and through continuous breeding, parents with good meat quality or high milk yield can be obtained.

Some wheat varieties have high yield under high water and fertilizer conditions, but because of their high plants and poor lodging resistance, when strong winds come, they will

Lodging in a large area not only affects the yield, but also is not easy to harvest. How can we get high-yield lodging-resistant varieties? Scientists use the strong lodging resistance of an ordinary dwarf wheat to cross this wheat with high yield and tall wheat, and then select plants with shorter stems, lodging resistance and higher yield from the offspring plants for propagation. After several generations of breeding, a new wheat variety with high yield, short stalk and lodging resistance was obtained.

In order to obtain excellent new varieties, people also use radiation and drug treatment to change the genetic material in seeds.

In plants developed from these seeds or their descendants, there will be various variations. It is possible to obtain new crop varieties by selecting beneficial variation types and directional breeding.

According to Baidu knowledge