Nose inheritance and evolution

When we walk on the street, we will find that many people have different sized noses. Some people have bigger noses, while others have small noses and high nose bridges. They do not need any plastic surgery at all, so this kind of nose is naturally very enviable. There are many conclusions about the inheritance and evolution of the nose.

1. Structural and material basis of genetic variation

(1) Structure of genetic variation

All characteristics of an organism are controlled by genes. Most genes in cells are regularly concentrated on chromosomes in the cell nucleus. Chromosomes are composed of proteins and DNA (deoxyribonucleic acid). The DNA molecule has a double helix structure, and its basic unit is deoxynucleotide, including deoxyribose, base and phosphate.

(2) Material basis of genetic variation

Genes are the material basis of genetic variation. Genes can not only pass genetic information to the next generation through replication, but also express genetic information. If there are differences in hair, skin color, eyes, nose, etc. between different races, it is due to genetic differences.

2. Genetic variation

(1) Genetic phenomenon

The phenomenon of similarities in traits between offspring and their parents, and between different individuals in the offspring. As the saying goes, “You reap what you sow.”

(2) Variation phenomenon

The phenomenon of differences in traits between offspring and their parents, and between different individuals in the offspring. For example, "One mother gave birth to nine sons, and each son was different."

3. Biological Evolution

(1) Biological evolution phenomenon

It is widely found in the biological world. Biological fossils provide the most powerful evidence for biological evolution.

(2) Main Views of Darwin’s Theory of Evolution

Darwin believed that overreproduction, struggle for survival, genetic variation and survival of the fittest were common phenomena in living things. The core of Darwin's theory of biological evolution is the theory of natural selection; the essence of natural selection is that the fittest survive and the unfit are eliminated (which is also the result of natural selection). The general direction of biological evolution is from simple to complex, from low to high, and from aquatic to terrestrial; and it is believed that the direction of biological evolution is determined by natural selection, and the driving force of biological evolution is the struggle for survival.