Dawkins "if we can't find how life started (with the DNA code) out of non-life structures, that would mean it's extremely unlikely we'll find life elsewhere as we would be the only living forms in the entire universe." and "If we can find on Earth (phil - or elsewhere in the solar system) that life can arise from something different from DNA or if we can find how the DNA started, then life would be all over the universe."

I really agree with that premise. To me that means that the best indication of interstellar life will come from a successfull biotek lab duplication of DNA's evolution. Alternatively, detection of indesputible biomarkers in the atmospheres of extrasolar planets. Possible detection of life on Mars is likely to be indistinguishable from Earth-Mars pansphermia.

Fact is, despite over a half century of space exploration, we have no scientific indication either way that life is nearly ubiquitous or that the Earth (and polluted nearby solar system objects) is the unique beneficiary of a once in the universe's existance improbable 10 exponent -50 or so event.