We are the only life form of the univers. Not even the only intelligent, but the only one. My arguments are:
Life is absolutely everywhere on earth. There is not a single isolated island or deep trench in the ocean that is not covered by life. If life can live elsewhere, univers would be covered by life. Some bacteria would have been ejected into space by some cataclysme and had colinized nearby planets. Kind of Fermi’s paradoxes.
Antropic argument. Our universe is suitable for life because if it weren’t, we simply wouldn’t be there. Add it to Okam razor. If a smaller, simpler, universe could handle life, we would be in that one. Not our current one.
“Our universe is so huge, so there must be other life form” is not the right statement. Our universe is so huge because it is the smallest universe where life could potentially appear.
Only my opinion, not a scientific demonstration.
How do you know the universe isn’t teeming with life? Our capability to observe the universe around us is pitiful.
I mean we are still figuring out whether there might be life on Mars. Most other solar bodies have scarcely been investigated for life. Let alone other solar systems. The reality is we have no idea.
Not only that, we don’t even have a good test for if something is or is not life. We know what water-based carbon life forms are on earth, but there may be other sets of conditions where self-replication is possible.
Stars are obviously self replicating and therefore alive. Large stars produce nebulae upon death which create new stars.
Hell, the concept of “life” itself is poorly defined.