It merely states what i've said before..
There are other organisms..
But they do not classify as higher lifeforms.
All the research they've done on Mars has brough forth?
That some kind of worm type of organism once existed.
Cause if im correct, there's no sign of them anymore.
Which would add up to the theory..
Most of the other planets are simply not suitable for life.

(I am probably wrong..But someone has got to oppose right)