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Latest David Bottjer Stories

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2008-10-07 10:34:46

Evidence suggests that 'sick Earth' extinctions more likely In geology as in cancer research, the silver bullet theory always gets the headlines and nearly always turns out to be wrong. For geologists who study mass extinctions, the silver bullet is a giant asteroid plunging to earth. But an asteroid is the prime suspect only in the most recent of five mass extinctions, said USC earth scientist David Bottjer. The cataclysm 65 million years ago wiped out the dinosaurs. "The other four have not...


Word of the Day
tessitura
  • The prevailing range of a vocal or instrumental part, within which most of the tones lie.
This word is Italian in origin and comes from the Latin 'textura,' web, structure.