Is Curiosity 100% sterile? If not, then the results will be contaminated.
Does vaporizing a rock from up to 25 feet away with a laser affect the rock's chemsty in any way?
Likewise, does heating rock to 1,800 degrees affect the rock's chemsty in any way?
When asked how life came to be on Earth, Richard Dawkins (and others) believe that life on Earth originated from Mars or some other planet, which still doesn't explain how life began.