Presentation is loading. Please wait.

Presentation is loading. Please wait.

Human Populations 02 June 20101Human-Populations.ppt.

Similar presentations


Presentation on theme: "Human Populations 02 June 20101Human-Populations.ppt."— Presentation transcript:

1 Human Populations 02 June 20101Human-Populations.ppt

2 Human populations grow slowly K-selected, Equilibrium species – Few large offspring – Parental care lasting > 10 yrs. – Birth interval 2-5 years in most of world. 02 June 2010 Human-Populations.ppt 2

3 Human population growth Historic growth – Exponential growth in recent times. – Carrying capacity? How much can human populations grow? 02 June 2010 Human-Populations.ppt 3

4 Human population growth Δ N = +B +I –D –E – B = birth rate = live births/1000 people/year – D = death rate = deaths/1000/year If B > D, population grows For most of human history B = D 02 June 2010 Human-Populations.ppt 4

5 Human Impact IPAT model I = P x A x T I = impact P = population size A = affluence T = technology I = P x A x T x S S = sensitivity 02 June 2010 Human-Populations.ppt5

6 Demography Population size Population density and distribution Age structure Sex ratios 02 June 2010 Human-Populations.ppt6

7 Demography Population density and distribution 02 June 2010 Human-Populations.ppt7

8 Demography Age structure – Slow growth vs. Rapid growth Sex ratios 02 June 2010 Human-Populations.ppt8

9 Demography Age structure Sex ratios – Chinas One-child policy 02 June 2010Human-Populations.ppt9

10 Age structure of USA Effect of baby-boom generation Baby-boomers now in most productive years; Soon to retire and draw Social Security; Soon to suffer medical needs of older age, need for nursing homes, hospitals, medical doctors; Needs MUST be met by smaller population of offspring. 02 June 2010 Human-Populations.ppt10

11 Human Population I = P x A x T Population size Affluence Technology 02 June 2010 Human-Populations.ppt11

12 Human Population Fertility rate Average number of children per female (lifetime) Replacement fertility rate Δ N = +B +I –D –E 02 June 2010 Human-Populations.ppt12

13 Demographic transition 02 June 2010 Human-Populations.ppt13

14 Demographic transition Birth/Fertility rates have changed. Fertility: – Total fertility rate Number of children a woman produces in childbearing years – Replacement-level fertility Number of children necessary to replace parents, To maintain constant population size ~ 2.1 per woman 02 June Human-Populations.ppt

15 Demographic transition Empowerment of women Rising standard of living Education influences fertility rate 02 June 2010 Human-Populations.ppt15

16 Demographic transition Empowerment of women Family planning Availability of contraception 02 June 2010 Human-Populations.ppt16

17 Demographic transition Factors affecting birth/fertility rates: – Children in labor force, – Urbanization, – Cost of raising & educating, – Opportunities for women, – Age at marriage, – Infant mortality, – Available contraception & abortion, – Religious & cultural values. 02 June Human-Populations.ppt

18 Infant mortality decline Improved food supply Proper nutrition (vitamins, protein, fats) Control of infectious disease. – Influenza – Diphtheria – Polio – Malaria – & more 02 June Human-Populations.ppt

19 Infant mortality decline Infant death for full term babies now rare in USA, N. Europe. Contrast to 19 th century. – Darwins children (born 1840s) – Enrico Caruso (1873 – 1923). 02 June Human-Populations.ppt

20 Recently, Have death rates changed? Life expectancy increased – Increased food supply, better nutrition – Sanitation/ personal hygiene – Medical care (immunization, antibiotics) – Safe water supplies – Decrease in infant mortality. 02 June Human-Populations.ppt

21 Demography Predicting the future of populations: Age structure diagrams – People age ! – Fertility rate – Death rate (age specific death rates) 02 June 2010 Human-Populations.ppt21


Download ppt "Human Populations 02 June 20101Human-Populations.ppt."

Similar presentations


Ads by Google