[Non-Ceph]: Origin of life?

tonmo

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Phil

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BBC news have just reported the discovery of a new hydrothermal vent system in the Indian Ocean. Not sure how long this has been known for, but the article seems to indicate this is a recent discovery:

Big 'smokers' found in Indian Ocean

Few details about the biological discoveries there, unfortunately.
 

tonmo

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Awesome!!

Hmm.... I'd like a hydrothermal vent Emoticon... and some coral Emoticons... Where's Tintenfisch??? :periscop:
 

Steve O'Shea

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..... and a 'sexy science' emoticon. Tintenfisch is paddling her way downstream somewhere (hopefully downstream anyway) - she'll be back at work ~ 15 August.
 

Fujisawas Sake

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Yo yo, peeps! (people) :lol:

Well, here's my two cents. NASA has done a lot of work dealing with research into extremophiles. No, these aren't life forms into extreme sports and such, rather they're life forms that exist under some rather nasty conditions. Like chemosynthetic bacteria in rocks, at hydrothermal vents and the like.

Here's a good link: EXTREMOPHILES

Life does find a way, and the formation and persistance of life in extreme situations does lead to an interesting thought: Life may be the rule, and not the exception in most planetary systems. Theoretically, extremophiles can exsist in harsh environments from the cold and radiation of space, to the dark crushing depths of the ocean. Europa's subglacial oceans may harbor such life forms, as may Mars.

I hope they find life on Mars... If they do, my Astronomy professor owes me five bucks.

Origin of life? Hey, its a possibilty.

Hell, so are squibbons....

Sushi and Sake,

John
 

Phil

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Thanks,

There are some very interesting links there. Here's just my opinion:

NASA seem to often flaunt the idea that there could potentially be hydrothermal vent systems in places such as Jupiter's moon Europa, based on evidence that there are cracks on the surface of this ice covered moon. The implication is there must be a warm core causing the ice covered surface to crack, move and refreeze driven by currents welling up from below causing the visual scarring so well documented by the Voyager probes, amongst others. Obviously Europa has an active core to create these currents, and hydrothermal vents must, therefore, exist. So far so good.

However, if one examines the hydrothermal vent fauna on this planet, practically every species seems to be a related to a surface living relative. Most of the animals that exist there seem to have migrated down from shallow surface waters over millions of years, slowly adapting and evolving to fit an increasingly hostile environment. So we have clams, crabs, shrimp and even octopi (Vulcanoctopus), and not strange animals with unique body plans which is what one might expect if the community had truly evolved independently at the vent system.

Even the Riftia tube worms, despite their unusual system of using sulphur fixing bacteria for energy are not unique; the animal has shallow water cousins that work in a similar manner. (Will try to find the reference, can't remember exactly where I read this).

So it seems, from my rather simplistic viewpoint, that in order for life to exist at hydrothermal vent systems, whether they be on Earth, Mars or Europa, the surface conditions must have been suitable for life to evolve first. I doubt if Europa ever had conditions even remotely favourable for the evolution of life, let alone complex life, being too cold and dark. Mars, well possibly, although we know the planet once had oceans, but the conditions now are very harsh. It stretches credibility to believe there could be a thriving system of complex life underground after hundreds of millions of years.

Even on earth, some of the the earliest fossils, stromatolites, evolved on the surface of the oceans absorbing nutrient from sunlight. This is why I have always been sceptical about these reports that complex life evolved at the hydrothermal vents and could exist elsewhere at these locations, if they exist, in the solar system. I seems to me that life moved to the vents, not originated there. :grad:

Perhaps I'm talking cobblers. Believe me, I'd love to be proved wrong though!
 

Fujisawas Sake

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No, that's actually a very good point. I forgot about the tube worms being annelids. Yeah, life probably would have migrated to the depths. I wonder about the bacteria that are found underground or in rocks. Extremophiles are wierd.

I wonder just under what conditions life can form? I still think that there are multiple vectors, just that we aren't used to thinking in terms of teh extraterestrial. Makes sense, we're only in the early stages of space exploration.

We'll "sea", won't we?

John
 

myopsida

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not strange animals with unique body plans which is what one might expect if the community had truly evolved independently at the vent system.
But if all surface life forms evolved from the vent fauna in the first instance they obviously would not have different body plans.
The question that needs to be answered is not where did life first evolve (salty spring/ice margin/volcanic vent) but How? Shifting the site, to say a comet, merely moves the question - it doesn't answer it.

I think the origin of life is related somehow to that noise they recorded which occured just before the Big Bang . . . it sounded like "bugger"
 

myopsida

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not strange animals with unique body plans which is what one might expect if the community had truly evolved independently at the vent system.
But if all surface life forms evolved from the vent fauna in the first instance they obviously would not have different body plans.
The question that needs to be answered is not where did life first evolve (salty spring/ice margin/volcanic vent) but How? Shifting the site, to say a comet, merely moves the question - it doesn't answer it.

I think the origin of life is related somehow to that noise they recorded which occured just before the Big Bang . . . it sounded like "bugger"
 

Phil

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myopsida said:
But if all surface life forms evolved from the vent fauna in the first instance they obviously would not have different body plans.
Good point, Myopsida.

However, the earliest complex fossilised eco-systems we have to examine are the Ediacaran faunas of Southern Australia of the late Precambrian. These were deposited in sandy conditions and were certainly deposited in shallow water. The rather peculiar animals in these deposits were deposited in tidal mudflats or deposited in tidal pools. There simply is no evidence, as far as I am aware, of deep water animal life before this early date.

Admittedly, it is possible that life could have evolved at hydrothermal vents before this date but there is simply no evidence for it. I suppose with the subduction of oceanic plate material under continental plates there are very few places (if any) in the world that contain sedimentary mid-oceanic depositions of a date of 600 million years or so to be examined.

Actually, if you are interested in strange marine life, the Ediacaran faunas are worth looking up. Most of those enigmatic creatures are uncertain as to their affiliation. There are weird mossy mattresses, quilted organisms, proto-sponges, no-body really knows what was going on. Even primitive molluscs(?)

Cheers!
 

amniote

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Still, it does seem that a lot of the creatures that hang out around the vents probably migrated to them from elsewhere. After all, the vents come and go with the movement of the plates and so the fauna that hangs out there must have some way - possibly in larval form - to move to other places. Vent ecosystems are small and specialised and do not have the biodiversity of a reef community or a deciduous forest. It seems more probable that the biodiversity of the surface waters would have seeded the vents rather than the biopaucity of the vents seeding the surface. Doubly so, given the idea that the vent fauna is very much clinging to existence. Surely one way to test whether the animals evolved there or not would be to see if any of them retain "vestigial" structures or behaviours that are essential to their surface relatives. Presumably such structures and behaviours would not have evolved in creatures which had never left the vent environment.



:grad:
 

Phil

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amniote said:
Still, it does seem that a lot of the creatures that hang out around the vents probably migrated to them from elsewhere.
Interesting point, Amniote, and I utterly agree with you.

Actually it believed that Riftia tube worm disperses its larvae via the hydrothermal plume itself. The juveniles are released and are carried up via the plume of hot water to parachute down and (hopefully) descend on the seabed in an advantageous position.
 

myopsida

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There simply is no evidence, as far as I am aware, of deep water animal life before this early date.
The assumtion is that early vents were in deepwater. Maybe there were shallow water vents and the deepwater vents we see today are just refugia?
 

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