Mineral formation
Biology and mineralogy can present many similar distribution patterns. Living things and inorganic things are both made up of energy and distribution of such leads to some intricate shapes. When I first saw the image you linked to I thought of veined feldspar.
feldspar image
It's a safe bet that the landers wont add much weight to any Martian life claims. That doesn't mean exobiology is not a real science, but rather,it is at present, a very underequipped and underfunded one in which to specialize. ;-)
Keep looking though!