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In late September 1838, he started reading Thomas Malthus's An Essay on the Principle of Population with its statistical argument that human populations, if unrestrained, breed beyond their means and struggle to survive. Darwin related this to the struggle for existence among wildlife and botanist de Candolle's "warring of the species" in plants; he immediately envisioned "a force like a hundred thousand wedges" pushing well-adapted variations into "gaps in the economy of nature", so that the survivors would pass on their form and abilities, and unfavourable variations would be destroyed. By December 1838, he had noted a similarity between the act of breeders selecting traits and a Malthusian Nature selecting among variants thrown up by "chance" so that "every part of newly acquired structure is fully practical and perfected".
Which book did Darwin begin reading in 1838?
A: An Essay on the Principle of Population

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Zhejiang was the site of the Neolithic cultures of the Hemudu and Liangzhu. A 2007 analysis of the DNA recovered from human remains in the archeological sites of prehistoric peoples along the Yangtze River shows high frequencies of haplogroup O1 in the Liangzhu culture, linking them to Austronesian and Tai-Kadai peoples.
What year was there an analysis of the DNA recovered from human remains in Liangzhu culture?
A: 2007

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According to one of her biographers, Giles St Aubyn, Victoria wrote an average of 2,500 words a day during her adult life. From July 1832 until just before her death, she kept a detailed journal, which eventually encompassed 122 volumes. After Victoria's death, her youngest daughter, Princess Beatrice, was appointed her literary executor. Beatrice transcribed and edited the diaries covering Victoria's accession onwards, and burned the originals in the process. Despite this destruction, much of the diaries still exist. In addition to Beatrice's edited copy, Lord Esher transcribed the volumes from 1832 to 1861 before Beatrice destroyed them. Part of Victoria's extensive correspondence has been published in volumes edited by A. C. Benson, Hector Bolitho, George Earle Buckle, Lord Esher, Roger Fulford, and Richard Hough among others.
What year did Victoria begin keeping a journal?
A: 1832

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At various times, there have been cardinals who had only received first tonsure and minor orders but not yet been ordained as deacons or priests. Though clerics, they were inaccurately called "lay cardinals" and were permitted to marry. Teodolfo Mertel was among the last of the lay cardinals. When he died in 1899 he was the last surviving cardinal who was not at least ordained a priest. With the revision of the Code of Canon Law promulgated in 1917 by Pope Benedict XV, only those who are already priests or bishops may be appointed cardinals. Since the time of Pope John XXIII a priest who is appointed a cardinal must be consecrated a bishop, unless he obtains a dispensation.
In what year did Pope Benedict XV revise the Code of Canon Law?
A:
1917