Earth is Probably Unique

[piscator]

Black smoker ecosystems with crabs skipping around in 150c water at 49 bar, grazing on worms that feed on plants that use use H2S instead of sunlight.




Jus sayin'

Sure.

And they have the same amino acids as me.

But, unlike me, they cannot be infected by the flu virus...

Indeed.

And unlike me, they would regard a steam boiler in a mountain locomotive as an appealing place to live and reproduce.

[rainbow]

FSM created all life, so we're all marinara based. Our bacteria will chow those aliens, assuming we don't find them tasty.

OK then, but who/what invented pasta?

You can't answer that one can you?

[rainbow]

mistermack wrote:

So if aliens have no immunity built up, they might well struggle.
Just like the American Injuns did against immigrant illnesses.

This example involves not only the same planetary biota, but the same species! Of course that was always going to happen. However, raccoons did not get decimated by smallpox...

Personally, I would doubt that the dead flesh from an alien biota would even be food for our decomposers. Our biochemistry effectively has a single origin, so we share the same amino acids, the same nucleic acids, the same phospholipids...

Alien analogues to these would be unlikely to have enzymes that could interact with them, for example.

You are, of course, absolutely correct.

The only chance they could be eaten by our bacteria, is if we had a common origin (which would beg a billion questions)

[mistermack]

Not so much.

It looks like life only evolved once, on Earth. So in over four billion years, only one KIND of life evolved on Earth. So it's pretty likely that that's the only kind that will evolve anywhere else.

Not for certain, by any means. But I'd say pretty likely.

If there were other likely kinds of life, you'd think that we'd have seen some sign of them evolving, on this goldilocks planet. Especially if they were types that were impervious to our microbes.

[rainbow]

Not so much.

It looks like life only evolved once, on Earth. So in over four billion years, only one KIND of life evolved on Earth. So it's pretty likely that that's the only kind that will evolve anywhere else.

Not for certain, by any means. But I'd say pretty likely.

Illogical, please recompute.

[mistermack]

Not so much.

It looks like life only evolved once, on Earth. So in over four billion years, only one KIND of life evolved on Earth. So it's pretty likely that that's the only kind that will evolve anywhere else.

Not for certain, by any means. But I'd say pretty likely.

Illogical, please recompute.

Bollocks. Please try harder.

[rainbow]

Not so much.

It looks like life only evolved once, on Earth. So in over four billion years, only one KIND of life evolved on Earth. So it's pretty likely that that's the only kind that will evolve anywhere else.

Not for certain, by any means. But I'd say pretty likely.

Illogical, please recompute.

Bollocks. Please try harder.

I'm not here to do your thinking for you.

Think of monkeys and typewriters.


http://news.bbc.co.uk/2/hi/3013959.stm

[mistermack]

I'm not here to do your thinking for you.
Think of monkeys and typewriters.

I do. Whenever you post. So what's new?

[Feck]

^ LOL

[rainbow]

I'm not here to do your thinking for you.
Think of monkeys and typewriters.

I do.

Yet you think that an exceedingly rare event such as the origin of life would follow the exact same sequence even on a different planet.

Did you forget to put on your thinking hat?

[pErvinalia]

How do you know it's rare? Did you forget to put your thinking hat on?

[rainbow]

How do you know it's rare?

That was the premise of missedahack's argument.

Please try to pay attention.

[pErvinalia]

No. It's too hard.

[mistermack]

I'm not here to do your thinking for you.
Think of monkeys and typewriters.

I do.

Yet you think that an exceedingly rare event such as the origin of life would follow the exact same sequence even on a different planet.

Did you forget to put on your thinking hat?

I think it's you that needs a new hat.
Rare events are usually rare, because there are very few ways they can happen.
If there were millions of ways for something to happen, it's not likely to be rare.

And on Earth, life only happened once, in 4.5 billion years, according to the geneticists.
That's mega rare. And that doesn't point to lots of ways it can happen.

I'm trying to keep it simple.

[JimC]

I'm not here to do your thinking for you.
Think of monkeys and typewriters.

I do.

Yet you think that an exceedingly rare event such as the origin of life would follow the exact same sequence even on a different planet.

Did you forget to put on your thinking hat?

I think it's you that needs a new hat.
A rare event is usually rare, because there are very few ways they can happen.
If there were millions of ways for something to happen, it's not likely to be rare.

And on Earth, life only happened once, in 4.5 billion years, according to the geneticists.
That's mega rare. And that doesn't point to lots of way it can happen.

I'm trying to keep it simple.

Now, to be fair, it has been suggested that it is possible that life could have originated many times on the early Earth, but only one start-up was successful, and drove the other, different biochemistries to extinction by resource competition. One would not expect to easily discover evidence for such failed biochemistries.