[guelo]

That is bad conjecture. We have no evidence of life anywhere besides earth, microbial or otherwise. Exoplanet research and this new data has found planets that could conceivably host life, but that's it.

[Symmetry]

Well, we do have evidence of past life on Mars - just not conclusive evidence. See

https://en.wikipedia.org/wiki/Allan_Hills_84001

and

https://en.wikipedia.org/wiki/Microbially_induced_sedimentar...

And, of course, that's not evidence that there's still life on Mars.