When were the immigrants in the forest?

(1) About10,000 to 20 million years ago, Australopithecus was mainly distributed in tropical and subtropical forests. Like chimpanzees today, they live a arboreal life. Later, as the climate gradually changed to dry and cold, a large area of forest became savanna, which greatly changed the living environment of Australopithecus. Due to the difference in adaptability of Australopithecus to the environment, some apes retreated from the edge of the forest to the depths, continued to live a arboreal life, and gradually evolved into modern apes. Others were forced to descend from trees to the ground, where they lived and eventually evolved into humans. In the process of living on the ground, they can't run fast to avoid the enemy because they don't have fangs and claws to attack and get food. Under such conditions, apes often walk only on their hind legs, but they liberate their forelimbs and gradually.

(2) Ye Wei, a French naturalist, said: It is man's upright walking that protects his head from the influence of the gravity of the earth and provides a broad space for the development of his brain, which makes his brain closer to the earth than the heads of other animals, because it can freely expand in all directions, making the area of his head and brain reach the maximum proportion, and making his brain have the smartest cognitive structure and thinking potential. It is his straight body that makes his senses play the greatest role and makes his eyes "see far and wide". So that the ears can hear voices from all directions and sit with the eyes to "see all the way and listen all around"; Let people feel the most exciting, touching, suggestive and all kinds of emotions and love that are difficult to express and describe. Engels once pointed out that walking upright is a "decisive step" in the process of transformation from apes to humans. The upright walking of the apes caused the division of labor between the forelimbs and hind legs, which enabled ancient humans to liberate their forelimbs and use tools. Forelimbs are more and more active, and upper limbs are more and more dexterous.

(3) Exploring late childbearing is beneficial for the country to control the excessive population growth, and for individuals, it is beneficial to the health, work and study of young people.

(4) It is assumed that couples A and their descendants were born at the age of 20. After 100, there will be five generations of descendants of A, and couples B and their descendants will be born at the age of 25. After 100, there will be four generations of descendants of B. 。

It can be seen that more people get married at the age of 20 than at the age of 25, and there will be an extra generation after 100, which shows that sticking to late marriage is conducive to controlling population growth.

(5) Suppose there are women in China who are 16 years old, 17 years old, 18 years old, 19 years old and 20 years old. If there is no requirement for late childbearing, the population will increase by 50 million as many women give birth to a child in five years. If there is a requirement for late childbearing, these women will not have children until they are 25 years old. Five years later, women who are only 20 years old will have100000 children, and the population will increase by100000.

If you insist on having children late for five years, there will be 40 million fewer people. Through data analysis, late childbearing is conducive to controlling population growth.

(6) Family planning has been defined as a basic national policy of China. The specific requirements of family planning are late marriage, late childbirth, fewer births and eugenics. According to the analysis of materials, the implementation of family planning can achieve the purpose of controlling the population and improving the quality of the population.

So the answer is: (1) A large number of forests have disappeared, and some forest apes have to live underground. Because of the changes in the environment and their own morphological structure, those forest apes can gradually walk upright, make and use tools, add brain development, communicate with fire and language, and finally evolve into humans.

(2) Walking upright liberates the forelimbs, makes tools and uses them, so that people's limbs can be stretched, and their ability to hunt and defend the enemy is greatly enhanced, making human beings stronger and stronger.

(3) Exploring late childbearing is beneficial for the country to control the excessive population growth, and for individuals, it is beneficial to the health, work and study of young people.

(4)5. 4. Late marriage is conducive to controlling population growth.

(5) 50 million,100000. Late childbearing is conducive to controlling population growth.

(6) population control