I intended to post this some time ago, but I've been too busy. Maybe most everyone has heard about it, but for those who haven't, it is interesting. A couple of months ago, several scientists reported that they found proto-DNA in a meteorite that collided with the Earth back in the 1960s. What this does is lend some support to the panspermia theory - that life on Earth came from someplace other than Earth.
Most scientists are not willing to go as far as stating "life came from outer space," but a few are suggesting that meteorites such as this one might have provided life on Earth with an evolutionary advantage.
The researchers did indeed check the meteorite to see if it was contaminated by material from Earth, and according to their findings, it was not. This rock came with its own proto-DNA. Members of the research time are quoted everywhere, and now here:
Lead author Dr Zita Martins, of the Department of Earth Science and Engineering at Imperial College London, says that the research may provide another piece of evidence explaining the evolution of early life. She says:
Of course the panspermia theory isn't new either. Speculation that life on Earth might have come from Mars, Europa, Titan, or other remote regions have existed for years. Fans of science fiction are likely thinking this is old news, and in that genre it is. In any case, it is certainly exciting to think about.
“We believe early life may have adopted nucleobases from meteoritic fragments for use in genetic coding which enabled them to pass on their successful features to subsequent generations.”
Between 3.8 to 4.5 billion years ago large numbers of rocks similar to the Murchison meteorite rained down on Earth at the time when primitive life was forming. The heavy bombardment would have dropped large amounts of meteorite material to the surface on planets like Earth and Mars.