Salt of the Early Earth

Astrobiology Magazine ^ | 2/6/05 | Leslie Mullen

[bayourod]

Does this mean I've been wasting money buyinmg expensive Sea salt?

[Fiddlstix]

BTTT

[lepton]

It seems to me that one of the arguments for an ocean development, at least in the line that begat animals, is not simply that we use salt, but that our bloods salinity is so close to that of ocean water...contemporary ocean water.

[lepton]

Scientists still have not figured out what triggered the enormous increase in the diversity of life in the Cambrian era.

Not decided, but possibly related to the development of sight.

[jungleboy]

yes

[LibWhacker]

Interesting (but not surprising!) that sight took so long to develop.

[blam]

"If the earliest life forms were halophiles, says Knauth, then perhaps we are really Martians."

Wouldn't suprise me a bit.

[TASMANIANRED]

Mars originally had much more salt than the Earth, and when Mars lost 50 to 90 percent of its water through evaporation it became even saltier. The Panspermia theory says that life originated elsewhere and then was transferred to Earth by meteors. If the earliest life forms were halophiles, says Knauth, then perhaps we are really Martians.

Where did the life on Mars come from.

Are they trying to claim that ancient Martian bacteria developed space travel when they didn't even have little hands to build space ships with.

Or are they suggesting that Mars exploded and blew a chunk of itself off and the little bacteria survived the explosion and traveled through space and managed a controlled entry in Earths atmosphere with out burning up.

Or perhaps the little bacteria with their advanced physics were able to pilot the meteor into a controlled entry into the atmosphere of Earth.

[blam]

Panspermia

I liked most of Sir Fred Hoyle's ideas.

[LiteKeeper]

INTREP - We could assume life began in outer space, but that would not prove any of the theories.

We could also assume that life was formed from the dust of the earth. After all, the basic components of our bodies correspond to the basic elements of the earth: Nitrogen, Carbon, Oxygen, Hydrogen.

[LibWhacker]

Or are they suggesting that Mars exploded and blew a chunk of itself off and the little bacteria survived the explosion and traveled through space and managed a controlled entry in Earths atmosphere with out burning up.

Meteor impacts blasted Martian surface material into space and it eventually entered Earth's atmosphere and rained down on the planet. AFAIK, heat is the enemy of bacteria, not acceleration -- at least not acceleration of the magnitude experienced by such ejecta. Presumably, some of this bacteria would be shielded from the intense heat of impact and entry into the Earth's atmosphere since it would be inside Martian rocks (and these we know do occasionally survive intact). Conceivably, it wouldn't take much to seed Earth with life. What I'd like to know is just how much acceleration a bacterium can survive. 100g's? 1000g's? Has anyone ever done the experiment?

[LibWhacker]

Thanks for that link! Bookmarked.

[TASMANIANRED]

I thought most meteors burned up in the earths atmosphere.

[LibWhacker]

Yes, many of them do, particularly the smaller ones. But some do make it to the surface.

Note this "panspermia" theory is all very hypothetical. Nothing's been proven yet. Except that bacteria can be revived after spending extended periods in the rigors of space. But exactly how long, I don't think anyone knows. Check out Blam's link above. Lots of good stuff there about it.

[PatrickHenry]

Is this thread pingable? I read the article, and I donno ...

[Junior]

It's a science thread and it goes to the formation of life on Earth -- both of which will bring the Luddites out in droves. I'd say ping the list.

[PatrickHenry]

EvolutionPing

A pro-evolution science list with over 230 names. See list's description at my homepage. FReepmail to be added/dropped.

[djf]

The thread might be, but the conclusion isn't.

Yes, the oceans might have had a much greater salinity 3.5 billion yrs ago. But I think large multicellular organisms have evolved much more recently, perhaps in the last 3-4 hundred million years.

And if an organism evolved in a fresh water environment became exposed to salt, it would do one thing. It would die. The dehydrating effects of salt in the diet would throw it totally out of kilter, a sort of feedback, where it started to dehydrate, drank more salty fluid to rehydrate, saline suicide.

[doc30]

It is also interesting that there is greater diversity of life in salt water environments than in fresh water. A part of this was the evolution of calcium based bones. Marine animals without bones depended upon the free calcium in ocean water. With the evolution of bones, fish could move into fresh water and survive because their bones would act as a calcium reservoir.