Thomas Lee Elifritz wrote yet another troll:
But I'll feed the troll anyway.....

The Mars rovers are not equipped with microscopes
good enough to see microbes. Also remember that
Earth did not have multicelluar life until about
600 million years ago. Which means that life on
Earth was single cell for 2 billion years. Which
suggests that it's hard for life to make that
jump, and maybe Mars life (if there is any) never
did that jump. All we can say with the rovers is that
we haven't seen any spiders on Mars, or turtles, but
we can't tell one way or another about microbes, alive
or fossil.