Visual evidence at this poor resolution is never going to impress or convince close minded critics. Nor will it provide proof of anything. I am pointing out unusual features that could have infinite explanations, in search of the simplest answer that adequately explains the observations. For me, microscopic lifeforms on the surface of Mars, now, or even more so in the past, is hardly some far out conclusion, rather a sound probability.

In the lower center of this picture, there are more dark grains that have unusual features.
Again, they are clinging in unlikely places, on positive curvatures, exposures, and slopes, while less dark material is seen in the small, dust trapping dimples. This example also shows additional unusual features in that the dark material is not only grain like, but also includes strands, loops, branches, etc. And since Halloween is close at hand, I think there are some micro spiders and snakes that you can see in those cracks too!