Question

before the 1858 publication of on the origin of species, charles darwin developed his theory of natural selection in five notebooks. in them he first expressed one of natural selections principles: that species produce more offspring than available resources can sustain. he also listed books he read, such as charles lyells elements of geology. a fall 1838 entry in one of darwins notebooks mentions species struggle for survival in a world of insufficient resources \as inference from malthus,
eferring to a 1798 essay by economist thomas malthus asserting that population growth will outpace agricultural production. a later notebook, begun in october 1838, mentions \the grand crush of population.\this suggests that______
which choice most logically completes the text?
a. though some of darwins notebook entries relating to his theory of natural selection date from 1838, others must have been written as late as 1858.
b. in early fall 1838, darwin realized that malthuss ideas regarding human populations derived from observations of animal behavior in nature.
c. sometime in or before october 1838, darwin determined thatapostulate rooted in economics might also be applicable to biology.
d. a key concept in darwins theory of natural selection had been previously articulated in the same terms by economists sometime between 1798 and 1838.

Explanation:

• Option A: The text focuses on the connection between Darwin's notebooks and Malthus's ideas, not on the date range of Darwin's notebook entries. So this option is not relevant.
• Option B: There is no mention in the text that Malthus's ideas about human populations came from animal behavior observations. This is an incorrect assumption.
• Option C: Darwin's 1838 notebook entry (mentioning species struggle for survival as an inference from Malthus, an economist) and the "grand crush of population" (in a notebook begun in October 1838) show that he was applying an economic - based (Malthusian) idea (population - resource imbalance) to biology (species survival).
• Option D: The text does not say that economists used the same terms as Darwin for the key concept of natural selection. It just shows a connection of ideas, not identical terminology.

Answer:

C. sometime in or before October 1838, Darwin determined that a postulate rooted in economics might also be applicable to biology.