Word: raup
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Dates: during 1980-1989
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...justification for this new idea came from a series of startling geological studies in the late 1970s by two University of Chicago geologists. David Raup and John Sepkowski. By carefully analyzing fossil records of the evolution of marine animals, the two concluded that large-scale extinctions occur about every 26 million years...
...hypothesis initially met plenty of opposition, and still does, Raup explains. For example, some believe there may have been a combination of factors leading to any or all of the extinctions, "It takes a lot of different types of stress such as climate changes to cause an extinction. It's a very muddy topic, "he says...