SAT Reading - Khan Diagnostic Quiz level 4 - reading 4

Questions 1-11 are based on the following
passage.


Adapted from Colin Butler, "Human Carrying Capacity and Human Health." © 2004 by Colin Butler. The passage refers to carrying capacity, or the maximum population size of a species that an environment can support.




The question of human overpopulation and its relationship

to human carrying capacity has been controversial for over

two centuries. In 1798 the Reverend Thomas Malthus put
forward the hypothesis that population growth would exceed
5 the growth of resources, leading to the periodic reduction of

human numbers by either “positive checks”, such as disease,

famine, and war, or “preventive checks”, by which (in the

absence of contraception) Malthus meant restrictions on

marriage. This “Malthusian view” was rapidly accepted by
10 most politicians, demographers, and the general public, and

remained popular until fairly recently.
Malthus's worst fears were not borne out through the

century following his death in 1834—food production largely

kept pace with the slowly growing global population.
15 However, soon after 1934, the global population began to rise

steeply as antibiotics, vaccines, and technology increased life

expectancy. By the 1960s, concerns of a mismatch between

global population and global food supply peaked—expressed

in books such as Paul Ehrlich's 1968 The Population Bomb.
20 This book predicted a future scarred by increasing famine,

epidemic, and war—the three main Malthusian positive

checks.
In 1966, United States President Lyndon Johnson shipped

wheat to India to avert a famine on the condition that the
25 country accelerate its already vigorous family planning

campaign. Johnson was part of an unbroken series of US

presidents concerned with the harmful effects of rapid

population growth in developing countries. This line

extended (at least) from John F. Kennedy to Jimmy Carter.
30 George H. W. Bush was also sympathetic to this view, prior

to becoming vice president in 1981.
But the 1970s surprised population watchers. Instead of

being a period shadowed by calamitous famine, the new crop

strains introduced by the “Green Revolution” (especially
35 grains such as rice, wheat, and maize) caused a dramatic

increase in the global production of cereals, the main source

of energy in the global diet. Among the development

community, despair turned into cautious optimism. By the

end of the decade, the public health community felt
40 sufficiently empowered to proclaim “Health for All by the

Year 2000”. Average life expectancy continued to zoom

upwards almost everywhere.

tab]The introduction of safe contraception contributed to a

apid fertility decline in many countries. But while the rate of
45 global population growth declined from its peak in the late

960s, the absolute increment of increase in annual global

opulation continued to grow. Most population-related

cientists, including food scientists and demographers, as

well as US President Jimmy Carter, continued to be very
50 concerned about global overpopulation. In 1970, the father of

the Green Revolution, the agricultural scientist Norman

Borlaug, was awarded the Nobel Peace Prize. In his Nobel

lecture, Borlaug warned that the success of the Green

Revolution would buy a breathing space for humankind of
55 three decades, unless equivalent action was taken to reduce

fertility rates.

Question 1 The primary purpose of the passage is to