What sort of life forms?
Bacteria-like? Possible.
Anything more complex? Possible.
Anything comparable with humans? Possible, but improbable.
A larger than usual brain requires huge amounts of energy – and doesn't automatically confer intelligence or wisdom. Apart from being an energy hog, a large brain results in confusion – only humans are so often so confused about fundamental things – child rearing and conflict resolution being prime examples.
No other species traumatises its offspring; chimpanzees make war and are terribly cruel; ants go to war if they need to: but humans lose all sense of proportion, and destroy everything, and surpass chimpanzees in our cruelty.
No other species would elect a Donald Trump as their leader (an assumption, I admit) or leave him there, once they woke up.
We are pretty dumb.
If the earliest humans were as dumb as us, why did they survive?
Maybe our stupidity was a recent acquisition, resulting from our terrible parenting practices, which stunt children's development.
But it's our huge brain that makes this possible.
Obviously our ancestors survived, but was it because of their bigger brains, or in spite of them?
Were they just lucky?
Whichever is the case, I doubt there is a fundamental need for, or drive to acquire, quite such a large brain as we have.
There may be parallels elsewhere in the universe, but I doubt it.
I hope there are. Imagine all the music and such our there if others exist!
Otoh, imagine all the cruelty and misery – and stupidity…

Just in our galaxy or in the entire universe? Neither of those are provable. Not unless we can actually visit the planets in question and thoroughly search, or unless they make themselves known.

Fermi assumes that alien civilizations are like we are and want to or need to colonize everything or let others know they exist.

The Drake Equation is similarly inaccurate as we probably wouldn't know the exact nature of aliens anyway. Maybe they are so technologically advanced that their equipment doesn't let off any type of signal.

What if aliens are so primitive that they don't have equipment at all? What if they aren't capable of building anything? What if they don't need the same variables that we do to remain alive?

There is a 50/50 probability as far as I'm concerned regarding whether there are aliens.

Evidently they haven't been to Miami Beach.

I think it is very likely that there is life beyond our solar system. However, the distances are so vast that we will probably never encounter extra-solar life.

Whatever doubts there may be about intelligent life on any other planets (I don’t hold those doubts personally), the existence of other planets on which life similar to ours COULD exist is highly likely.

It is not a foregone conclusion that the conditions suitable for life will have given rise to life, especially intelligent life - there are far too many other variables. On that basis, there quite probably is plenty of real estate out there that is unoccupied, and suitable for us.

The only real obstacle we face is getting to any of those other places. The journeys are far too long for even one human lifespan, often more than that. So we’d be looking at suspended animation and AI controlled vehicles. Or generation ships, but human nature would most likely see those crash and burn due to social pressures and mass disillusionment and anger before the second generation died off.

We need the theoretically possible warp drive before we can go anywhere outside our own system.

Because there is nowhere else to go, so we should "save our planet", is not a logical reach. It is already too late to save this humans life on this planet. According to Stephen Hawkins (before he died), the human-caused global warming has become self-sustaining and will accelerate even if all other human factors are eliminated. He said that Earth will be similar to Venus and it is all over for mankind within 100 years. It is bend-over-and-kiss-our-butts-goodby time folks.

We can trash this one because when we die we will all be going to a worlderful after life. Says so right here in this book. Written by bronze age goat herders so it must be literal truth.

Fermi’s Paradox and the Drake Equation...

They're just using new made-up variables. The truth of it is that nobody really knows what the odds are that life will begin on a new planet or what the odds are that the life will develop into intelligent beings. We have only blackboards and guessing so far and we probably won't know until we begin real exploration.

While I completely agree with you about taking care of our planet of origin, I believe we'll move outward into near space, then our solar system.....

We have not found life on other planets.. Our only chance is to lockup owners who own everything. When it comes down to final survival, the power of the people who always win out throughout human history.

Being a person who has attempted to build 3 self substainable green eco villages. My conclusion is the synthetic system is rigged. It was illegal to live off the Corperationism Grid.

After we lock up the world greatest criminals, bankers and a few politicans.

Then we must build domed encloses a large urban area under a single roof for the danger of sun and floods if we don't recover. The dome is airtight and pressurized, creating a habitat that can be controlled for air temperature, composition and quality, typically due to an external atmosphere (or lack thereof) that is inimical to habitation for one or more reasons. Domed cities have been a fixture of science fiction and futurology since the early 20th century, and may be situated on Earth, a moon or other planet.

If people think Mars is an alternative we are way behind schedule

The point of this is that it's really all guesswork. We don't know how common life is (at the microbial level), we don't know the likelihood of microbial life evolving into multicellular life, and we don't know the likelihood on multicellular life evolving intelligence...and even with all that, if we encountered another intelligent species, we might not recognize them as such (consider our very limited understanding of animal cognition).

Bad news bro, we're doomed. check out www.naturebatslast.com We have about 10 years before we all die. Live well while you can. PS Considering there are more galaxies than all the grains of sand on all the beaches on the earth....the chance of life is still expotentially great.

How would we "fall back on" another planet, exactly? Maybe ship some vials of DNA and hope the good folks there would reconstitute them? Take care of this planet, period!

Humans are so arrogant to even suggest that we are the ONLY life in the hundred billion galaxies we claim to know exist

It is a worry though, we are unable to keep ours maintained and are destroying its balance, yet we think we can turn an inter stellar hell into a livable environment?

Let’s just concentrate on this planet and not destroying it, not because there may or may not be life elsewhere, but because we care enough for this wonderful, amazing one we live on now!

No one has colonized the galaxy, not because life/intelligent life has not evolved on other planets, but because no one (aliens), have not concurred (whoops...typo, "conquered" )the speed-of-light barrier...which may be unconquerable.