Copyright © 2006, Elsevier Inc. All rights reserved C HAPTER 13 Human Population Growth and Family...

Copyright © 2006, Elsevier Inc. All rights reserved

CHAPTER 13Human Population Growth and Family Planning


FIGURE 13-1 THREE TYPES OF AGE PYRAMIDS. (A) POPULATION IS GROWING BECAUSE OF A LARGE PROPORTION OF JUVENILES. (B) THE POPULATION IS STABLE; NOTE THE SIMILAR PROPORTION OF REPRODUCTIVE ADULTS AND JUVENILES AND THE RELATIVELY LARGE PROPORTION OF POSTREPRODUCTIVE ADULTS COMPARED WITH (A). (C) POPULATION IS DECLINING BECAUSE THE PREPONDERANCE OF POSTREPRODUCTIVE ADULTS MEANS THAT THE DEATH RATE IS HIGH, WHILE THE BIRTH RATE IS LOW


FIGURE 13-2 THE EXPONENTIAL GROWTH CURVE OF A POPULATION UNDER OPTIMAL ENVIRONMENTAL CONDITIONS.


FIGURE 13-3 ENVIRONMENTAL RESISTANCE CAUSES A POPULATION PREVIOUSLY EXPRESSING ITS BIOTIC POTENTIAL TO LEVEL OFF AT THE CARRYING CAPACITY OF THE ENVIRONMENT.


FIGURE 13-4 WHEN POPULATION GROWTH EXCEEDS THE CARRYING CAPACITY OF THE ENVIRONMENT, COMPONENTS OF THE ENVIRONMENT ARE DESTROYED AND THE POPULATION MAY CRASH


FIGURE 13-5 EVEN EXTREMELY SMALL PERCENTAGE ANNUAL GROWTH RATES PRODUCE RAPID POPULATION INCREASES


FIGURE 13-6 GROWTH OF THE WORLD’S POPULATION. AT THE BEGINNING OF THE CHRISTIAN ERA, THE WORLD POPULATION IS ESTIMATED TO HAVE BEEN 300 MILLION. THE 1650 POPULATION OF 500 MILLION HAD DOUBLED BY THE YEAR 1830 TO 1 BILLION PEOPLE. IN THE PAST 100 YEARS, THE GROWTH RATE HAS ACCELERATED GREATLY. BY THE YEAR 2000, THE EARTH HAD APPROXIMATELY 6 BILLION INHABITANTS. NOTE THE SIMILARITY OF THIS CURVE TO THAT IN FIG. 13-2.


FIGURE 13-7 PRESENT AND PROJECTED FUTURE POPULATION SIZES IN THE ENTIRE WORLD AND IN COUNTRIES OF VARYING DEGREES OF DEVELOPMENT (1994 TO 2050). DATA FROM THE UNITED NATIONS. MORE DEVELOPED, EUROPE, NORTH AMERICA, AUSTRALIA–NEW ZEALAND, AND JAPAN; LESS DEVELOPED, AFRICA, ASIA (EXCEPT JAPAN), LATIN AMERICA, AND SOME AREAS OF OCEANIA. NOTE THAT THE MOST GROWTH WILL OCCUR IN THE LESS-DEVELOPED COUNTRIES THAT ALREADY HAVE THE GREATEST POPULATIONS (E.G., CHINA, INDIA, AFRICA)


BOX 1: WORLD CONTRACEPTIVE USE AND FERTILITY RATES


FIGURE 13-8 BIRTH RATES AND DEATH RATES IN THE UNITED STATES FROM 1930 TO 2005. WHENEVER BIRTH RATE EXCEEDS DEATH RATE, A POPULATION IS GROWING. NOTE THAT THE DEATH RATE HAS BEEN DECLINING SLOWLY, BUT THE BIRTH RATE HAS FLUCTUATED. THE PEAK IN BIRTHS IN THE 1950S REPRESENTS THE POST-WORLD WAR II “BABY BOOM.”


FIGURE 13-9 DIFFERING PREDICTIONS FOR POPULATION SIZE IN THE UNITED STATES, DEPENDING ON A FAMILY SIZE OF TWO (– – –) OR THREE (– • – • – •) CHILDREN. THESE PROJECTIONS ASSUME SMALL FUTURE REDUCTIONS IN MORTALITY AND CONTINUATION OF IMMIGRATION AT THE PRESENT LEVEL.


BOX 2: GOVERNMENT-ENFORCED POPULATION CONTROL IN CHINA

Copyright © 2006, Elsevier Inc. All rights reserved C HAPTER 13 Human Population Growth and Family...

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