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Bài giảng Tính động ở quần thể người trình bày các nội dung chính sau: Lịch sử phát triển dân số / quần thể người, độ lớn của dân số bị ảnh hưởng bởi sinh, khả năng sinh sản, tử vong, di cư, nhập cư như thế nào, dân số bị ảnh hưởng bởi tỷ lệ nam và nữ ở mỗi độ tuổi như thế nào, những yếu tố ảnh hưởng đến kích cỡ dân số,... Mời các bạn cùng tham khảo để nắm nội dung chi tiết.
TÍNH ĐỘNG Ở QUÂN THỂ NGUOI HUMAN POPULATION DYNAMICS GS LÊ HOÀNG NINH Các vấn đề cần lưu ý Lịch sử phát triển dân số / quần thể người liêu có người vào năm 2050? Đô lớn dân số bị ảnh hưởng sinh, khả sinh sản, tử vong, di cư, nhập cư nào? Dân số bị ảnh hưởng tỷ lệ nam nữ độ tuổi nào? Chúng ta làm chậm phát triển dân số nào? Nghiên cứu trường hợp : dân số giới đông ? The world’s population is projected to increase from 6.6 billion to 8.9 billion between 2006 and 2050 The debate over interactions among population growth, economic growth, politics, and moral beliefs is one of the most important and controversial issues in environmental science Core Case Study: Is the World Overpopulated? Much of the world’s population growth occurs in developing countries like China and India Figure 9-1 Core Case Study: Is the World Overpopulated? Some argue that the planet has too many people Some feel that the world can support billions of more people due to technological advances There is a constant debate over the need to reduce population growth Must consider moral, religious, and personal freedom HUMAN POPULATION GROWTH: A BRIEF HISTORY The human population has grown rapidly because of the expansion of agriculture and industrial production and lower death rates from improvements in hygiene and medicine In 2006, the population of developed countries grew exponentially at 0.1% per year Developing countries grew (15 times faster at 1.5% per year Where Are We Headed? We not know how long we can continue increasing the earth’s carrying capacity for humans There are likely to be between 7.2-10.6 billion people on earth by 2050 97% of growth in developing countries living in acute poverty What is the optimum sustainable population of the earth based on the cultural carrying capacity? Where Are We Headed? U.N world population projection based on women having an average of 2.5 (high), 2.0 (medium), or 1.5 (low) children Figure 9-2 High High 10.6 Medium Low Medium 8.9 Low 7.2 Year Fig 9-2, p 173 Những yếu tố ảnh hưởng đến kích cỡ dân số Population increases because of births and immigration and decreases through deaths and emigration Instead of using raw numbers, crude birth rates and crude death rates are used (based on total number of births or deaths per 1,000 people in a population) Urban areas must import most of its food, water, energy, minerals, & other resources They produce enormous quantities of wastes that can pollute the air, water & land 44% of the world’s people live in urban areas that occupy only 5% of the world’s land & they consume 75% of the world’s resources Reasons for World Hunger Issues Unequal distribution of available food Loss of arable land Increasing population growth rate Increasing poverty in developing countries Reasons the human population has been so dramatic in the last century The Industrial Revolution Modern Medicine Fertility rates & reduction Environmental pressures of urbanization from population growth are reduced because birth rates in urban areas usually are 34 X’s lower than in rural areas Cities provide education opportunities Some countries, including China, penalize couples who have more than one or two children by: Raising their taxes Charging other fees Eliminating income tax deductions for a couple’s third child Loss of health-care benefits, food allotments and job options In China couples who pledge to have no more than one child receive Extra food Larger pensions Better housing Free medical care Salary bonuses Free school tuition for their one child Preferential treatment in employment when their child enters the job market However, according to some studies, there is a strong preference for male children Girls are aborted at a higher rate than boys Some infant girls are killed Male children sometimes are fed better than female children SOLUTIONS: INFLUENCING POPULATION SIZE Family planning has been a major factor in reducing the number of births and abortions throughout most of the world Women tend to have fewer children if they are: Educated Hold a paying job outside the home Do not have their human right suppressed SOLUTIONS: INFLUENCING POPULATION SIZE The best way to slow population growth is a combination of: Investing in family planning Reducing poverty Elevating the status of women Factors that affect birth & fertility rates Importance of kids in labor force Urbanization Cost of raising & educating kids Availability of private & public pensions Religious beliefs, traditions & cultural norms Educational & employment opportunities Infant mortality rate Average age at marriage Availability of reliable birth control 1994 Global Summit on Population & Development Cairo, Egypt Encouraged action to stabilized the world’s population at 7.8 billion by 2050, instead of the projected 1112.5 billion The major goals are to: Provide universal access to family-planning services Improve the health care of infants, children & pregnant women Encourage development of national population policies Improving the status of women by expanding education & job opportunities Major goals continued: Increase access to education for girls Increase men’s involvement in childrearing responsibility & family planning Take steps to eradicate poverty Reduce & eliminate unsustainable patterns of production & consumption Annual Rate of Natural Population Change (%)= Birth rate – Death rate x 1,000 people 100 Declining Fertility Rates: Fewer Babies per Women The replacement level to sustain a population is 2.0 children In 2006, the average global Total Fertility Rate was 2.7 children per woman 1.6 in developed countries (down from 2.5 in 1950) 3.0 in developing countries (down from 6.5 in 1950) ... Lịch sử phát triển dân số / quần thể người liêu có người vào năm 2050? Đơ lớn dân số bị ảnh hưởng sinh, khả sinh sản, tử vong, di cư, nhập cư nào? Dân số bị ảnh hưởng tỷ lệ nam nữ độ tuổi nào?... (high), 2.0 (medium), or 1.5 (low) children Figure 9-2 High High 10.6 Medium Low Medium 8.9 Low 7.2 Year Fig 9-2 , p 173 Những yếu tố ảnh hưởng đến kích cỡ dân số Population increases because... live Figure 8-1 1 Late loss Early loss Age Fig 8-1 1, p 169 FACTORS AFFECTING HUMAN POPULATION SIZE Average crude and birth rates for various groupings of countries in 2006 Figure 9-3 Average crude