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The function of the highlighted sentence is primarily to
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The passage suggests that Duke Ellington' s early recorded jazz works
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Geologists can determine the ages of rocks and fossils by using natural clocks, including the natural decay of unstable, radioactive atoms into stable forms. The element uranium occurs in minute concentrations in seawater, and certain types of organisms, particularly corals, absorb it as they grow. One isotope of uranium, 238U, decays through a series of steps to 230Th, an isotope of thorium. As a coral grows, it adds tiny amounts of 238U to its skeleton. Over time, this 238U steadily transforms into 230Th. The proportion of the two isotopes changes in a predictable way over time, allowing us to calculate the ages of fossil corals in marine terraces back as far as five hundred thousand years.
A drawback of uranium-thorium dating is that it doesn't work on most fossils. Shells of molluscs like clams and snails are common in marine terrace deposits, but molluscs don't take up uranium from Seawater. Here, though, we have another trick: amino acid racemization. The proteins of living creatures
contain amino acids in a specific molecular shape known as the L-configuration. Upon death, some of these amino acids begin shape-shifting to a new arrangement called the D-configuration-a process called racemization. Molluscs are particularly useful for amino acid dating because they live practically everywhere in shallow ocean habitats and because
their shells are bound together with matrixes of amino acid-rich proteins. By measuring the ratio of the two types of amino acids in mollusc shell proteins, we can estimate the time since death.
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The author of the passage would most likely agree with which of the following statements about 238U?
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The highlighted sentence serves primarily to
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The passage implies which of the following about differences between fossil molluscs and fossil corals?
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The scientific method is not radically different from the rational attitude in everyday life or in other domains of human knowledge. Historians, detectives, and plumbers-indeed, all human beings-use the same basic methods of induction, deduction, and assessment of evidence as do physicists or biochemists. Modern science tries to carry out these operations in a more careful and systematic way by using controls and statistical tests, insisting on replication, and so forth. Moreover, scientific measurements are often much more precise than everyday observations; they allow us to discover hitherto unknown phenomena, and they often lead to discoveries that conflict with "common sense.” But the conflict is at the level of conclusions, not the basic approach.
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The passage implles that one difference between modern science and "the rational attitude in everyday life" is that modern science
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Which of the following best describes the function of the highlighted sentence in the context of the passage as a whole?
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The large merchants who dominated long-distance trade in the Spanish empire for the better part of three centuries have been traditionally depicted by historians as a privileged group that used its political and financial clout to protect its interests while engaging in uncompetitive economic practices, largely to the detriment of Spain and its colonies. This image suggested specifically that the colonial commercial system was irrationally organized, choked Spain's economic progress, and generated unwarranted monopoly rents [profits], all for the benefit of the privileged traders of the merchant guilds.
None of these conclusions are wholly incorrect, but they largely fail to appreciate the unpredictable environment in which these traders engaged. Without having adequately reflected on the role of risk in oceanic commerce, historians have tended to paint an overly one-dimensional portrait of the large merchants and their commercial practices. Long-distance traders responded to conditions of poor information, tremendous uncertainty, and endemic risk by adopting defensive strategies and embracing risk-reducing institutions. Avoiding risk, however, neither meant that the Spanish merchants lacked entrepreneurial spirit nor that they were somehow the precapitalist rentiers that historians sometimes imply. To the contrary, no merchant could operate in the highly risky Atlantic world trade without constantly anticipating and taking active measures to avoid catastrophe.
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The primary purpose of the passage is to
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Which of the following can be inferred from the passage about the "defensive strategies" ?
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The author and the historians mentioned in the first sentence would probably agree on which of the following issues?
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Historical preservation societies preserve old structures to educate visitors about local history. These groups generally choose to preserve old houses that are considered beautiful, leaving less aesthetically pleasing structures to be demolished. Thus, by giving visitors the impression that all old buildings are beautiful, the groups systematically misrepresent history.
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Which of the following, if true, casts the most doubt on the argument?
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That the narrator in George Eliot's novel Middlemarch (completed 1871) displays an astonishing breadth of knowledge may be partly explained by Eliot's reaction to a specializing division of labor that threatened an extinction of generalists. Some of Eliot's contemporaries attributed the nineteenth century's rapid specialization to an accelerating pace of knowledge production. But specialization, Eliot recognized, was not simply an effect of proliferating Information. The notion that specialization was essential to an individual's credibility was also an ideological product of professionalization. Nineteenth-century professional organizations actively fostered public distrust of nonprofessionals, an effect, Eliot feared, that might pressure laypersons, confronted with unfamiliar fields, to resign their curiosity and abdicate moral authority, conceding decision-making to professionals. Eliot's narrator serves as her rejoinder: an ideal of intellectual expansiveness.
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According to the passage, Eliot differed from some of her "contemporaries" in that she
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The author mentions the "extinction" primarily to
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From a biological perspective, culture may be broadly defined as shared variation in behavior that is generated and maintained by social learning-through imitation or teaching, for example. Social learning in animals is often difficult to demonstrate directly. But the presence of culture can be established by observation and deduction: when behavioral differences exist that cannot be accounted for by genetic or environmental factors, cultural transmission must be occurring. Critics respond that it is often difficult to rule out hypotheses that genes or learned individual responses to differing environments are responsible for behavioral patterns. Often implicit in this argument is the notion that social learning, considered a more complex and more cognitively demanding phenomenon than individual learning, should be invoked only as an explanation of last resort.
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According to the passage, the occurrence of social learning can be established by
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