More results for the possibility of Life on Mars - Page 14

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Kevin Author Profile Page



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PostPosted: January 23, 2012 10:59 AM 

Sometimes the most simple things can explain some of the most complicated questions. In the experiment using yeast it domonstrates how single cell creatures started to form into more complex creatures.

http://www.universetoday.com/92850/key-step-in-evolution-replicated-by-scientists-with-yeast/">
http://www.universetoday.com/92850/key-step-in-evolution-replicated-by-scientists-with-yeast/

Kevin Author Profile Page



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PostPosted: January 23, 2012 11:00 AM 

That link did not work so well, take 2, cut and paste into the browser might be best:

http://www.universetoday.com/92850/key-step-in-evolution-replicated-by-scientists-with-yeast/

Kevin Author Profile Page



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PostPosted: January 23, 2012 11:10 AM 

Ooops sorry missed #257 apologies

Serpens


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PostPosted: January 23, 2012 11:22 PM 

Kevin. Damn. If it is so simple then why did it take so very very long to happen on Earth. Lack of centifuges?

Barsoomer


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PostPosted: January 24, 2012 12:34 AM 

Lack of oxygen.

Serpens


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PostPosted: January 24, 2012 3:10 AM 

Oh...like on Mars!

MPJ


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PostPosted: January 24, 2012 4:54 AM 

I think this experiment showed that single celled organism can evolve to multi celled organism if it yields enough benefits over the single celled entities quite quick - oxygen is no factor here in the first place but selection pressure.

Here is another one from the extreme life frontline:
Extreme Life at the Bottom of a Glacier
[link]

By the way: respiration is what the Viking labeled release experiment was aimed to probe for.

http://en.wikipedia.org/wiki/Cellular_respiration

Kevin Author Profile Page



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PostPosted: January 24, 2012 5:22 AM 

There was no Oxygen on Earth until plant life came along, the atmosphere was very toxic as volcanic activity was very high. The idea that rivers, lakes oceans plus oxygen are essential ingredients for life are no longer that valid.

Many theories exist about the Primordial Soup that existed on Earth over 500 million years ago and the single cell life that lived in it. Triggering the advancement of that life form could have been down to Lightening, Ultraviolet light, Shock and Heat (Meteorite/Comet impact).

So why did it take so long? Perhaps waiting for the sequence of all the right conditions and events to happen. Maybe more complex life started earlier and got wiped out eventually starting again and finding a foot hold to evolve over time.

Serpens


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PostPosted: January 24, 2012 6:07 AM 

I think this experiment showed that single celled organism can evolve to multi celled organism if it yields enough benefits over the single celled entities quite quick

Really? Lacking centrifuges it took billions of years for multicellular organisms to appear.

Kevin. I though that oxygen was the third most abundent element in the universe and would have been plentiful on early Earth. I guess you mean free atmospheric oxygen? I thought that Cyanobacteria was the culprit in contaminating the early atmosphere with oxygen molecules - but it would be a bit of a stretch to call that initial photosynthetic bacteria plant life.

MPJ


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PostPosted: January 24, 2012 6:59 AM 

"Really? Lacking centrifuges it took billions of years for multicellular organisms to appear."

But its has been demonstrated that multicellularity doesn't take long to develop(evolve) if required and that it isn't such big hurdle as thought. We still dont really know what triggered the sudden emergence of multicellularity after ages of single celled life on Earth - certainly not centrifuges thats right. Smile

Barsoomer


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PostPosted: January 24, 2012 3:48 PM 

http://biology.stackexchange.com/questions/709/did-researchers-evolve-multicellular-yeast-or-did-they-just-turn-on-multicellula

Yeast is already a fairly complex organism, a fungus. One criticism of the research was that yeast "de-evolved" from a multi-cellular fungus. The authors answer this criticism in the above exchange.

Kevin Author Profile Page



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PostPosted: January 25, 2012 5:39 AM 

Serpens - yes in the atmosphere, there were Seas so Oxygen existed here and so did the majority of early life forms. Hydrothermal Vents would have done their bit deep down, I live in hope that similar things are happening deep beneath the surface of Mars and other Moons in our Solar System. I would expect Archaea to be inhabiting these worlds.

MPJ


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PostPosted: January 26, 2012 8:40 AM 

Iron/sulfur metabolizing microbes found living on dead hydrothermal vents:
[link]

General remark: Its is not yet clear if life came into existence on Earth in the first place (its the working theory at the moment though as no proof for et-life is yet accepted ) - from our knowledge now it could as well have developed somewhere else and brought here. My "hidden bet" is comets by the way but whats needed: more research on Earth and other celestial bodies. The research of et-life on Mars would be a major leap for lifting those secrets. Smile

dx


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PostPosted: January 28, 2012 3:19 PM 

Kevin>>>

I like what you say here, "Sometimes the most simple things can explain some of the most complicated questions".

I'll explain it later.

yt
dx

Serpens


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PostPosted: January 28, 2012 7:20 PM 

MPJ. The research of et-life on Mars would be a major leap for lifting those secrets. Alternatively such research could come up dry. Earth could be an anomaly where an unlikely sequence of evengs caused life to evolve. Similar to the extremely unlikely factors that underpin our universe. As I have mentioned before it was possibly the combination of liquid water and the very close proximity of the moon creating miles high tides and stirring up everything that was the defining influence. The moon, migrating outwards reducing in influence but still providing a (declining) rotational stability prevented the huge climate swings that would have plagued Mars.

Ben


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PostPosted: January 28, 2012 7:55 PM 

Serpens; When did the moon get in its present position ? I vaguely remember studying long shore bars dated around 300 Million years old that suggested they formed in current tidal conditions.

Barsoomer


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PostPosted: January 28, 2012 8:28 PM 

Serpens, even if your speculation that Earth was uniquely suited to the genesis of life is correct, the recent evidence (see Water on Mars thread) for an ocean on Mars in the late Hesperian (~ 3 Byr ago) should be considered.

Earth was teeming with microbial life by then, and it seems inevitable that meteorites would have transported spores from Earth to that ocean on Mars.

Serpens


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PostPosted: January 28, 2012 10:45 PM 

Ben. The moon formed during the early Hadean. It was outside the Earth's roche limit (around 10,000 km)and r was approx 18,000 km. The Earth's rotational period at that time was some 6 hours so you can imagine the huge tidal bulge (and not just water.

Basic physics. The Moon keeps the tidal bulge aligned to itself but the Earth is trying to carry it along in it's rotation. So the Earth loses angular momentum until today we have a sedate 24 hour rotation and time to enjoy the sunset. There is no free lunch and the trade off is that the lost angular momentum is transferred to the moon which consequently raises to a higher orbit. While gravity has an inverse square relationship tidal force is inverse cubed. So yes, A mere 300,OOO years ago the tidal effect wouldn't be all that much different to today. But 3 - 4 billion years ago? We cannot really even imagine the effect!

Barsoomer. it is pretty easy for ejecta from Mars to cross Earth's orbit if it has martian escape velocity. After all Earth is between Mars and the centre of mass of the solar system. But escape velocity from Earth requires a heck of a lot more energy, plus sufficient to excess to withstand the deceleration due to the sun and cross Mars orbit (which covers a much greater distance than Earths). Probability of an Earth genesis meterorite impacting Mars? Pretty damn low (not impossible but don't hold your breath).

Barsoomer


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PostPosted: January 28, 2012 11:59 PM 

http://homepage.mac.com/mpaineau/filechute/paine_amec2010_transpermia.pdf

This paper estimates that a half a ton of Earth material from the Chicxulub impact alone would have reached Mars.

This is little doubt that impacts can remove material from Earth. The initial impact does not have to impart enough energy to reach Mars; gravitational interactions with the Moon or near-Earth asteroids can do that.

Elementary orbital mechanics implies that moving from a Mars orbit to an Earth orbit has the same difficulty as a transfer in the opposite direction. In one case, it has to lose orbital velocity and in the other gain it, but the magnitude of the change is the same.

Kye Goodwin


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PostPosted: January 29, 2012 3:48 AM 

We just don't know if Earth life originated on Earth or was seeded from elsewhere. I'm inclined to guess the later because the Earth genesis theory could be the sort of mistake we humans often make: thinking that we are at the center of the universe. Its BIg out there and now extra-solar planets are turning out to be very common. It could be that life arises from non-life fairly easily and spreads rarely, but I'm guessing the opposite.

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