According to available physical and biological evidence, when did multicellular organisms first appear on the Earth?

0 votes
     a few thousand years ago
      about 1 billion years ago
      about 3 billion years ago
      about 200 million years ago
      about 1 million years ago
asked Sep 20, 2012 in Astronomy by anonymous
    

1 Answer

0 votes
about 1 billion years ago
answered Sep 22, 2012 by SkyStar ~Expert~ (2,855 points)



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