EVOLUTION
EVIDENCE FOR EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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at the top of a vertical timeline and the right side of a horizontal timeline
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at the top of a hortizontal timeline and the bottom of a vertical timeline
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at the bottom of a vertical timeline and the left side of a horizontal timeline
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Detailed explanation-1: -The principle of superposition states that in an undeformed sequence of sedimentary rocks, each layer of rock is older than the one above it and younger than the one below it (Figures 1 and 2). Accordingly, the oldest rocks in a sequence are at the bottom and the youngest rocks are at the top.
Detailed explanation-2: -The oldest subdivision of the time scale is the Precambrian (symbolized by PC, X, Y, or Z in the GRI GIS data). The Precambrian is split into three eons: Hadean (4600-4000 MYA), Archean (4000-2500 MYA), and Proterozoic (2500-541 MYA).
Detailed explanation-3: -Older rocks are at the bottom, and younger rocks are at the top. The early geologic time scale could only show the order of events. The discovery of radioactivity in the late 1800s changed that. Scientists could determine the exact age of some rocks in years.
Detailed explanation-4: -Over time, the sediments pile up to form horizontal layers of sedimentary rocks. The bottom layer of rock forms first, which means it is oldest. Each layer above that is younger, and the top layer is youngest of all.
Detailed explanation-5: -The oldest fossils are between 3 billion and 3.5 billion years old.