Something cause Mars to be in a present state.. That could have happened...
I suppose an extensive search on Mars would be necessary. Then, we should know much much more about its past. It would be amazing if there were fossils on Mars.
It's all about the mass. Mars is just to tiny to sustain a thick atmosphere (which would keep the water under pressure and thus in liquid form). Plus, it doesn't have a huge, spinning molten iron ball in the middle of it to help with a nice, shielding magnetic field like Earth's (which would keep the Solar wind from blowing away its atmosphere). If we hadn't been hit by that Mars-sized rock a few billion years ago, Earth would probably look a lot like Mars right now.