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Panspermia theory?
May 22, 2017 at 11:09 am
I was watching a show the other day that mentioned panspermia as the current theory explaining the origin of life on Earth.
I don't have an issue with the theory (if it is REALLY a theory; hypothesis if it's not there yet) I do have a question that nobody seems to answer...
It's obvious that life started somewhere (duh.) Why are they speculating that life had to start somewhere else and then move to Earth? Is it not more likely that life just began here as the simplest form imaginable rather than the alternative: Live evolved elsewhere to the extent that it could survive a massive meteor impact and many years of space travel to be transplanted here?
Obviously life had to start and evolve in either scenario; but, panspermia seems to necessitate even more 'long odds' events to happen than if life just evolved here to begin with. There may be some evidence that I haven't been made aware of in which case I welcome any references.
Thoughts?
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RE: Panspermia theory?
May 22, 2017 at 11:15 am
(This post was last modified: May 22, 2017 at 11:15 am by Foxaèr.)
Panspermia is certainly more probable than the god theory.
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RE: Panspermia theory?
May 22, 2017 at 11:18 am
The universe had 10 billion years to work with before our solar system even formed.
That's a long time to pass.
Meanwhile, the god shit is only a couple of thousand years old at best. I guess he was sitting on a cloud jerking off for most of that time.
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RE: Panspermia theory?
May 22, 2017 at 11:23 am
Panspermia posits that life started in one place and expanded from there. "There" would have be very near "Here" for that stuff to just drift around in space until it found a suitable environment. Now, given that life appears to have started here very early on, and probably died off several times before the planet settled down, the coincidental timing is extraordinary.
If we get out into space and "panspermia" particles are floating around everywhere then this might be likely, sorta. But if that original life didn't start in this galaxy then the odds go down drastically. Random radiation of particles would require huge amounts of them to accidentally land here. Also, if that original life source were a good ways away it wouldn't be here yet unless there's some mechanism we don't know about in action.
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RE: Panspermia theory?
May 22, 2017 at 12:00 pm
God didn't do it. We can just drop that.
It seemed to me that panspermia was over complicating things; but, I see now how it may just be considering other possible sources if the conditions on earth were uncertain. Also, if conditions were better on another place (like mars or wherever not too far away) before earth was viable, panspermia could allow more time for life to start. It could have began elsewhere while the earth was still a ball of flaming rocks only to show up later when conditions were better and be a little ahead of the game.
Although, the majority of the diversity we see now evolved in the 500M+ years since the Cambrian 'explosion' leaving an easy couple of billion years of time to get going prior to that...
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RE: Panspermia theory?
May 22, 2017 at 12:17 pm
Those other places have gods that we just don't. So unfair.
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RE: Panspermia theory?
May 22, 2017 at 12:48 pm
My initial thoughts on it is that it sounds plausible until we consider the vast distances and likely velocity of a complex molecule. Basically, not only must it evolve somewhere stable, some catastrophic event must accelerate it to near light speed without damaging it, and is has to be close enough not to be dispersed into insignificance and/or be precisely aimed in our direction at just the right time in our planet's development. The odds are staggering that a sufficiently complex molecule could be so lucky to beat a homegrown solution.
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RE: Panspermia theory?
May 22, 2017 at 1:14 pm
It seems to me the main thing that gave panspermia a boost in recent years is the discovery that:
1. There is far more life on earth that reside deep underground in cracks and cavities in rocks than we realized just 20-30 years ago. Prior to 1980s, the conception of life on earth is the sun is the ultimate power source of all the chemical energy life on earth uses, and vast majority of life on earth must be residing at, above or just barely below its solid surface. We now thing up to half of all of the earth's biomass resides deep underground and may be largely independent of any chemical process Drive by the sun. These life are often extremely frugal of available resources and may wake up for major biochemical events on the order of once every many years. So Life that lives deep underground seems far more capable of surviving an meteoric impact on its origin world, long trips through interstellar distances encased in rock fragments, and then revive on a wide range of destination environments.
2. The different bodies in the solar system exchanged far more material through ejecta from meteoritic impacts then we realized. The total amount of debris from meteoric impacts exchanged between inner planets may be many thousands of cubic miles.
So it becomes plausible if life originate on one body in the solar system, then sizeable volumes of live specimens may have been distributed to major bodies over the life of the solar system.
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RE: Panspermia theory?
May 22, 2017 at 1:24 pm
But that only supports the notion that life arising on other planets may wind up on planets where life has already arisen. If the conditions are right to support the alien forms, it would probably also initiate abiogenesis here.
