U.S. Population Projections

3. U.S. Population Projections Three population scenarios for the United States based on differing fertilities rates and immigration of 450,000 persons per year. (Redrawn from Westoff, C.F. “Fertility in the United States.” Science 234:554-559.)

4. B M Mortality Rate Birthrate K Population Density

7. Average Annual Rate of Population for Various Groups of Countries in 1993 (Data from Population Reference Bureau)

12. Developing Countries 50 Crude Birth Rate 40 Rate of Natural Increase Crude Death Rate 30 Rate per 1,000 people 20 10 0 1775 1800 1850 1900 1950 2000 2050 Year

13. Developed Countries 50 Rate of Natural Increase = Crude Birth Rate – Crude Death Rate 40 Rate of Natural Increase 30 Crude Birth Rate Rate per 1,000 people 20 Crude Death Rate 10 0 1775 1800 1850 1900 1950 2000 2050 Year

14. Birth and Death Rates in Mexico, 1900 to 1995 50 Birth Rate 40 30 Rate per 1,000 people 20 Overall Population Increase Rate of Natural Increase Rate of Natural Increase Death Rate 10 0 1800 1850 1900 1975 2000 Time Both birth and death rates decline during the 20th century, but because the death rates declined much more than the birth rate, Mexico has experienced a high growth rate. (The high death rate prior to 1920 was caused by the Mexican Revolution.)

19. Number of Children a Woman Has Varies with Education 3.2 2.8 2.4 2 1.6 Children Born per Woman 1.2 0.8 0.4 0 Not high School graduate High School graduate College 4 years College 5+ years Shown are the 1987 fertility rates for 35- to 44-year-old women in the United States with differing levels of education.

22. Projected Changes in the Ethnic Composition of the U.S. Population Between 1980 and 2080 In 1980 In 2080 (If current trends continue) Whites 79.9% Whites 49.9% Asians, others 12.0% Blacks 14.7% Blacks 11.7% Hispanics 23.4% Asians, others 2.0% Hispanics 6.4% (Data from the Population Reference Bureau)

23. Rural Cities less than 1 million Cities more than 1 million Patterns of World Urbanization from 1900 to 1985 with Projections to 2020 2020 1985 37.5 1950 1900 56.7 35.4 27.1 71.1 86.4 27.5 15.8 21.4 7.5 1.6 12 1.6 2.5 4.9 8.1 World Population in Billions (percent) Data from United Nations and Population Reference Bureau

24. Urbanization of Various Groups of Countries, 1950 - 2000 29% 41% World 48% 64% North America 77% 78% 61% 70% Oceania 73% 56% 75% Europe 79% 39% 66% USSR 74% 41% Latin America 69% 77% 20% 29% Asia 55% 15% 31% Africa 42% 1950 1990 2000 (Data from United Nations and Population Reference Bureau)

25. Tracking the Baby-boom Generation Age structure of the U.S. Population in 1955, 1985, 2015 and 2035 (Data from Population Reference Bureau and U.S. Census Bureau)

26. Postreproductive Reproductive Prereproductive A Expanding B Stable C Diminishing Population Types Age structure of populations: (A) an expanding population, with a very large proportion of young individuals; (B) a stable population, with relatively equal prereproductive and reproductive age groups; and ( C) a diminishing population, with a low percentage of young individuals.

27. Population Age Structure Diagrams for Countries with Rapid, Slow, Zero, and Negative Population Growth Rates Male Female Male Female Male Female Male Female Rapid Growth Kenya Nigeria Saudi Arabia Slow Growth United States Australia Canada Zero Growth Denmark Austria Italty Negative Growth Germany Bulgaria Hungary Ages 45 - 85+ Bottom portions represent prereproductive years (ages 0-14), middle portions represent reproductive years (ages 15-44), and top portions represent postreproductive years (ages 45-85+). (Data from Population Reference Bureau) Ages 15 - 44 Ages 0 - 14

29. Age Class (years) Today (percent) 2050 (percent) 0-17 26.5 24.0 18-44 42.8 35.3 45-64 18.9 23.7 65 and over 11.8 17.0 Approximate Age Distribution in the United States at the Present Time and in 2050 Assuming a stationary population size of about 275 million. Based on pages 6-7 of the Statistical Abstract of the United States, 97th ed., Bureau of the Census, 1976. Current age distribution is from table 25, Statistical Abstract of the United States, 106th ed., 1985.

31. Age 75+ 70–74 65–69 60–64 55–59 50–54 45–49 40–44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 0–4 60 40 20 0 0 20 40 60 Population (Millions) Projected Chinese Population in 2032 If Fertility Rate Reached 1.0 by 1992 Males Females (Source: H. Yuan Tien, Population Today, April 1984, p. 7)

32. Chinese Birth Planning Campaigns

33. x (years) 0 1 2 3 4 1x 1.0 0.5 0.25 0.125 0 mx 0 3 3 3 0 1xmx 0 1.5 0.75 0.375 0 R0=2.625 Answer: The information provided allows us to set up the following 1xmx table, from which R0 is computed:

34. Reproductive Parameters for Daphnia magna Cohorts Fed a Range of Chlamydomonas Concentrations at 20oC Food Concentration (Cells cm–3) 103 104 105 106 Percent Reproducing 50 87 97 50 Eggs per Brood 2.8 2.6 15.5 21.1 Broods per Female 1.7 7.5 8.2 3.4 Days Between Broods 5.4 3.6 3.1 3.3 Age at First Brood (days) 23.4 16.9 9.8 9.1 Net Reproductive Rate (R0) 2.25 16.23 99.33 34.80 Exponential Rate of Increase ( r ) 0.03 0.10 0.28 0.20 Source: Porter et al. 1983.

36. 1000 Rotifer Human Hydra Gull 100 Black-tail Deer Number of Survivors 10 Oyster 1 0 20 40 60 80 100 Percent of Total Life Span

37. 1000 700 500 300 100 70 50 Number of Survivors 30 Human female 10 Human male 7 5 Black-tail female 3 Black-tail Male 1 0 10 20 30 40 50 60 70 80 90 100 Percent of Total Life Span

38. 1000 700 500 300 100 70 50 Number of Survivors 30 Wild-type 10 Quintuple 7 5 Speck 3 Vestigial 1 0 10 20 30 40 50 60 70 80 90 100 Percent of Total Life Span

39. Survivorship Curves For the Population of Sweden over Several Centuries 1000 1959 1931-1940 800 1891-1900 600 Survivors per 1,000 Live Births 1816-1840 400 1757-1763 200 0 0 20 40 60 80 100 Age (Years) Note that as health conditions improved and the standard of living increased over the years, the survivorship curves began to approach physiological life span, changing from concave to convex. (From Clark, 1967)

40. 17.5 Norway 17.0 16.5 Germany 16.0 Finland Sweden 15.5 Age at Menarche (Years) 15.0 14.5 U.S.A. 14.0 Denmark 13.5 Great Britain 13.0 1840 1860 1880 1900 1920 1940 1960 Year of Menarche

42. Age (x) Survivorship (lx ) Expectation of Life Ex (see below) 0 1.0 3.40 1 0.8 3.00 2 0.6 2.67 3 0.4 2.50 4 0.4 1.50 5 0.2 1.00 6 0.0 0.00 Expectation of life: E0 = (l0 + l1 + l2 + l3 + l4 + l5 ) = (1.0 + 0.8 + 0.6 + 0.4 + 0.4 + 0.2)/1.0 = 3.4/1.0 E1 = (l1 + l2 + l3 + l4 + l5)/l1 = (0.8 + 0.6 + 0.4 + 0.4 + 0.2)/0.8 = 2.4/0.8 = 3.0 E2 = (l2 + l3 + l4 + l5)/l2 = (0.6 + 0.4 + 0.4 + 0.2)/0.6 = 1.6/0.6 = 2.67 E3 = (l3 + l4 + l5)/l3 = (0.4 + 0.4 + 0.2)/0.4 = 1.0/0.4 = 2.5 E4 = (l4 + l5)/l4 = (0.4 + 0.2)/0.4 = 0.6/0.4 = 1.5 E5 = l5/l5 = 0.2/0.2 = 1.0 Illustration of the Calculation of Ex in a Hypothetical Stable Population with Discrete Age Classes, Using Equations (1) to (4)

49. The Common Mud Turtle’s Generation Time is Close to that of Other Organisms of Similar Size 100 m Sequoia Fir Whale Kelp Birch 10 m Balsam Dogwood Rhino Elephant Elk Bear Man Deer 1 m Snake Fox Beaver Salamander Rat Horseshoe crab Crab 10 cm Turtle Mouse Newt Scallop Frog Snail Chameleon Bee Oyster Length 1 cm Horse fly House fly Clam Drosophila Daphnia 1 mm Stentor Paramecium 100 m Didinium Tetrahymena Euglena Spirochaeta 10 m E. coli Pseudomonas B. aureus 1 m 1 day 1 year 1 hour 1 week 1 month 10 years 100 years Generation time