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just as DNA may have replaced an earlier form of life. What might that form of life have been like? Was it on earth? Where did it go? Why don't we see any fos

by pj 17y ago

just as DNA may have replaced an earlier form of life. What might that form of life have been like? Was it on earth? Where did it go? Why don't we see any fossil or other remnants of it?

mixmax 17y ago
Without being an expert I believe that science leans toward the theory that RNA, or something similar, preceeded DNA.
berntb 17y ago
If that happened, it was certainly a good time before there were multicellular life. Hence, no remnants. There are some hints that there was an RNA-based world before DNA. A strong one is that ribosomes is made partly from RNA.
burke 17y ago
http://en.wikipedia.org/wiki/RNA_world_hypothesis http://en.wikipedia.org/wiki/RNA_world_hypothesis I seem to remember hearing about some organism that only has RNA, but I couldn't find it with a quick search through wikipedia.
- ilyak 17y ago
  Are viruses organisms? They aren't, but they only have RNA.
- berntb 17y ago
  An interesting link, if you have organic chemistry interests but haven't read that much on pre-RNA. Thanks, should have checked that myself.
kragen 17y ago
The Precambrian fossil record is pretty thin, even though DNA-based Precambrian life existed for about six times as long as we've had multicellular organisms. There's a discussion at http://en.wikipedia.org/wiki/Origin_of_life#From_organic_molecules_to_protocells http://en.wikipedia.org/wiki/Origin_of_life#From_organic_mol...