Steve Jackson Games Forums

Steve Jackson Games Forums (http://forums.sjgames.com/index.php)
-   GURPS (http://forums.sjgames.com/forumdisplay.php?f=13)
-   -   [Space] Panspermia and the Campgaign (http://forums.sjgames.com/showthread.php?t=125887)

scc 05-17-2014 01:07 AM

[Space] Panspermia and the Campgaign
 
OK, in a campaign setting I'm working on for a Space game involving a single multi-star system I'm planning on using Panspermia as an explanation for why there are so many habitable plants.

This neatly solves two problems: Why are all these planets inhabitable and why can they interact with them (In other words why can we eat the plants and animals that evolved there)

But from the look of things there might be a few problems with that. While Bacteria, fungi and other single celled lifeforms. But what about slightly bigger lifeforms, could plant seeds have made interplanetary or borderline interstellar trips clinging to the side of a meteorite?

And the big one: If I assume the planet that humanity evolved on is the one where life first arose on, the planet closest to that, at a mere 1.28 AU, has a high chance of have sentient or near-sentient life. What do people think are the chances of that happening? And what are the odds that people realize it before things are too late? And is any sort of communication possible?

Flyndaran 05-17-2014 03:08 AM

Re: [Space] Panspermia and the Campgaign
 
Magic 8 ball: Answer hazy, ask again later.

We have one world known to have life. And only one intelligent species on that world in the past 4.54 billion years. We can't know much other than it seems that human level sapience is damn unlikely.

Flyndaran 05-17-2014 03:10 AM

Re: [Space] Panspermia and the Campgaign
 
Panspermia seems a bit silly. Unless you expand it to include simple amino acid seeding by meteorites.
But for a setting, you can just hand wave it with the law of really big numbers. After enough material exchanges eventually one will contain viable life.

scc 05-17-2014 04:01 AM

Re: [Space] Panspermia and the Campgaign
 
I'm pretty sure that there was a rock found from Mars that showed signs of carrying bacteria, that turned out to have come from Earth to begin with (The rock went from Earth, to Mars and then back again) so it's possible

Nereidalbel 05-17-2014 04:59 AM

Re: [Space] Panspermia and the Campgaign
 
Planets being habitable is not explained be panspermia; that's just being the right distance from the parent star. As for being able to eat plants on other worlds, that's just luck. Billions of years of evolution are more than enough to create large differences, as well as planets having differing chemical compositions.

scc 05-17-2014 05:40 AM

Re: [Space] Panspermia and the Campgaign
 
It being in the right temperature zone means the planet has the POTENIAL to support life. It also has to be big enough to retain the right elements and an atmosphere. Once those criteria are meet an interesting paradox arises, life begets life, in basic terms you need the first beginnings of life to kickstart the entire thing to higher and higher levels. In simple terms if you kill off all the trees on Earth, it will soon be life less

malloyd 05-17-2014 06:06 AM

Re: [Space] Panspermia and the Campgaign
 
Quote:

Originally Posted by scc (Post 1763083)
But from the look of things there might be a few problems with that. While Bacteria, fungi and other single celled lifeforms. But what about slightly bigger lifeforms, could plant seeds have made interplanetary or borderline interstellar trips clinging to the side of a meteorite?

Likely not, they'd burn off during reentry. They'd need to be inside the meteorite to have a chance. Which doesn't seem a whole lot less likely than the bacteria I suppose. Does it matter? Unless you have time travelers go back and look, or I suppose happen to turn up the records of the terraformers, you are never going to be *certain* where the life on any world came from.

Quote:

And the big one: If I assume the planet that humanity evolved on is the one where life first arose on, the planet closest to that, at a mere 1.28 AU, has a high chance of have sentient or near-sentient life. What do people think are the chances of that happening?
We have no idea - the problem of extrapolating from a tiny sample. Once we have managed to look for life on more than two worlds, and found at least one more biosphere, we might be able to say something that wasn't a pretty much a guess. The lack of any evidence of a second sentient species evolving here on Earth at some point in it's history suggests the odds aren't wildly in favor of it, but really they could be anything from several percent per geologic period to, well, anything down to just above zero.

Quote:

And what are the odds that people realize it before things are too late? And is any sort of communication possible?
With something genuinely intelligent, it's probably fairly obvious and some level of communication is just about certain, eventually. Near-sentient it's much harder to say, not least because that's an even harder to define concept. Again, does it matter? You are never going to get universal agreement - small sample size is against you again. Pick whichever one makes the campaign premise work better.

aesir23 05-17-2014 08:26 AM

Re: [Space] Panspermia and the Campgaign
 
Quote:

Originally Posted by scc (Post 1763083)
But from the look of things there might be a few problems with that. While Bacteria, fungi and other single celled lifeforms. But what about slightly bigger lifeforms, could plant seeds have made interplanetary or borderline interstellar trips clinging to the side of a meteorite?

One solution to this is to simply decide that there's an unknown mechanism by which certain patterns of evolution repeat themselves.

e.g. on every planet, some strands of the original extremophile bacteria (that have seeded so many planets) tend to evolve into photosynthetic plant life--whenever that happens, animals evolve to take advantage of the oxygen surplus and the potential food source represented by the autotrophs.

This is hand-wavy, of course, and ignores the random nature of natural selection, but it would explain why there's edible plant life where ever you go without having to posit seeds that survive the trip through space.

I would even suggest that the extremophile bacteria (likely the first life-form) evolved on a comet, and was spread to other comets and planets by collisions.

Nereidalbel 05-17-2014 08:47 AM

Re: [Space] Panspermia and the Campgaign
 
If your star system has some ice ball planets and/or moons at the outer reaches, life could evolve in the oceans underneath icy crusts, and occasionally be thrown out into space via geysers. I mean, there has to be a reason tardigrades can survive floating around in space and such...

Also, if any microbial life could go dormant and float around in space for a period of time without needing to hitch a ride on an asteroid or comet, they could feasibly float into an atmosphere without being roasted.

thrash 05-17-2014 09:03 AM

Re: [Space] Panspermia and the Campgaign
 
Quote:

Originally Posted by scc (Post 1763109)
I'm pretty sure that there was a rock found from Mars that showed signs of carrying bacteria, that turned out to have come from Earth to begin with (The rock went from Earth, to Mars and then back again) so it's possible

Do you have a cite for that? I just finished a graduate level class in meteorites, and ALH84001 has unequivocal Martian isotope ratios, not terrestrial. The 'fossils' are controversial, not the origin.

Panspermia would most likely work on the scale of bacteria and other single-celled organisms, not more complex life. The result would be ecosystems descended from the same progenitors, but not necessarily more closely related than, say, humans and the tube worms that live in black smokers on mid-ocean ridges.


All times are GMT -6. The time now is 08:39 PM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.