meaningful Martian microbes...maybe

IN THE i on Saturday I discovered (on Sunday; I am usually a day late reading the paper) a comment from Science Editor Steve Connor talking about our 'fascination with the Red Planet'.  Always interested in such things I proceeded to read on as he referred to the most recent discoveries implying the previous existence of running water on Mars, and the inference that if there is water, there could be life, or at least, there could have been, once upon a time.

So far, so good.  Still interested.  But my interest became irritation at this paragraph:

"A universe where life is so common [i.e. on both Earth and Mars, in whatever form the latter took] would presumably be governed by the same rules of Darwinian evolution that produced intelligent, conscious human beings on Earth.  Discovering even the simplest life form on Mars, therefore, would almost certainly mean the existence of advanced, intelligent aliens in other solar systems." - italics mine.

This made my eyebrows do a few things.  But I don't think the jump they made is as big as the jump he makes.  Almost certainly?  Even allowing for the 'almost', the 'certainly' was an eyebrow aggravator.
Now, I cannot tell you whether there is extra-terrestrial life out there, intelligent or not.  Alas, you'll be sad to hear I am not gifted by such knowledge.  I am not threatened by the prospect, but I understand that even if there were other intelligent life forms out there, the likelihood that the timing would be so in tune with our own development that we could actually be in contact is - well, teeny, to use a very scientific term.

I have a vague memory of reading something somewhere sometime (as ever, beautifully accurate in my references) that the proximity of Earth and Mars could reasonably mean that some kind of microbe exchange could have gone on in the early stages of its formation, with all the collisions that took place in our solar system...the ingredients for life, it could be assumed, may indeed have 'crossed over' between the two planets during the rocky and violent making of our solar system.  This being the case, any life found on Mars (and they've not found it yet) may not be as independent of Earth as we may think.  (That's a very convoluted summary of something I can't remember very well, so please don't take my word for it.)

If signs of life are discovered on Mars it will indeed be fascinating, but I'm not sure I will be able to say that this implies 'almost certainly' that there is intelligent life on other planets.  That is beyond my knowledge and, as I've said, such an inference is rather aggravating to my eyebrows.

Image source: NASA - definitely not me.