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Cladistics is another method of classification. A clade is a taxonomic group of organisms consisting of a single common ancestor and all the descendants of that ancestor. Every creature produced by sexual reproduction has two immediate lineages, one maternal and one paternal. Whereas Carl Linnaeus established a taxonomy of living organisms based on anatomical similarities and differences, cladistics seeks to establish a taxonomythe phylogenetic treebased on genetic similarities and differences and tracing the process of acquisition of multiple characteristics by single organisms. Some researchers have tried to clarify the idea of race by equating it to the biological idea of the clade. Often mitochondrial DNA or Y chromosome sequences are used to study ancient human migration paths. These single-locus sources of DNA do not recombine and are inherited from a single parent. Individuals from the various continental groups tend to be more similar to one another than to people from other continents, and tracing either mitochondrial DNA or non-recombinant Y-chromosome DNA explains how people in one place may be largely derived from people in some remote location.
Which chromosome sequences are used to study ancient human migration paths?
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The answer: Y

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The Compact Disc is an evolution of LaserDisc technology, where a focused laser beam is used that enables the high information density required for high-quality digital audio signals. Prototypes were developed by Philips and Sony independently in the late 1970s. In 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. After a year of experimentation and discussion, the Red Book CD-DA standard was published in 1980. After their commercial release in 1982, compact discs and their players were extremely popular. Despite costing up to $1,000, over 400,000 CD players were sold in the United States between 1983 and 1984. The success of the compact disc has been credited to the cooperation between Philips and Sony, who came together to agree upon and develop compatible hardware. The unified design of the compact disc allowed consumers to purchase any disc or player from any company, and allowed the CD to dominate the at-home music market unchallenged.
What year did CD players become available for purchase?
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The answer: 1982

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Mexico City, or the City of Mexico (Spanish: Ciudad de Mexico audio (helpinfo) American Spanish: [sjua() e mexiko]; abbreviated as "CDMX"), is the capital of Mexico. As an "alpha" global city, Mexico City is one of the most important financial centers in the Americas. It is located in the Valley of Mexico (Valle de Mexico), a large valley in the high plateaus at the center of Mexico, at an altitude of 2,240 metres (7,350 ft). The city consists of sixteen municipalities (previously called boroughs).
How many meters above sea is Mexico City?
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The answer: 2,240

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The Bourbon Restoration followed the ousting of Napoleon I of France in 1814. The Allies restored the Bourbon Dynasty to the French throne. The ensuing period is called the Restoration, following French usage, and is characterized by a sharp conservative reaction and the re-establishment of the Roman Catholic Church as a power in French politics. The July Monarchy was a period of liberal constitutional monarchy in France under King Louis-Philippe starting with the July Revolution (or Three Glorious Days) of 1830 and ending with the Revolution of 1848. The Second Empire was the Imperial Bonapartist regime of Napoleon III from 1852 to 1870, between the Second Republic and the Third Republic, in France.
What is the second empires?
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The answer:
the Imperial Bonapartist regime of Napoleon III