Microbes are advanced life

[SorryDave]

A lot of the search for life in our solar system focuses on the detection of single cell microbes at sources of water. This is partly because they existed early in earths history and have been found in fairly exotic locations on earth, and always require water.

I believe that it is possible, even likely, that life originated outside of earth. This is not a rare position anymore in origin theories. However, I believe that if this is true it is something other than single cell microbes that is the dominating life form.

Space fairing life may be much simpler. I can imagine an environment where the objects that our now the contents of cells live in ecosystems. This would stretch the definition of life as the systems would "replicate" through a symbiotic relationship not yet observed in nature.

Some landed on a rare liquid water surface and developed the ability to enclose their environment with lipids. Over millions of years they developed the ability to survive as replicating single cells in what was previously a toxic environment of water.

Until the development of multicellular life, these single celled creatures were the most advanced form of life which permeates our solar system and other stars.

What do you guys think,.,

Edited September 12, 2014 by SorryDave

[Tommygun]

Something like a virus or RNA life form?

[SorryDave]

Something like a virus or RNA life form?

Even simpler and more exotic by our understanding, but nearly as difficult to detect. Most virus could not replicate without a host cell to do all the work, the simplest being just protected strands of RNA.

I imagine a.community of these simple objects would replicate only as a community, but would not need to exist in a closed system.

They may exist in another type of system where local variations and "blends" of individuals would allow the replication of the entire system.

Maybe they would exist on some organic/mineral/carbon substrate with large areas that fail to replicate once resources are consumed, but small patches were replication of the system continues in a cycle.

The reactions could occur at a lower rate with long periods of dormancy and stability that is only activated occasionally.

[crubs]

Viruses and ribozymes aren't considered lifeforms at all. The term "simple lifeform" is an oxymoron, because all life as we understand it is erratically complex. I consider viruses and self-replicating ribozymes (if such a thing can or ever has existed) to be non-living organisms. A self-replicating ribozyme is currently the simplest non-living organism that natural models allow for, and yet we don't even know what this would look like if it can exist, or if it has existed. And as unstable as ribozymes are, I doubt they are capable of panspermia.

From what I can see, undirected panspermia requires high a degree of complexity so that an organism has the machinery necessary to deal with the harshness of space.

[SorryDave]

From what I can see, undirected panspermia requires high a degree of complexity so that an organism has the machinery necessary to deal with the harshness of space.

It is complex machinery that would be the most susceptible to damage from space. Redundancy does not require complexity and would be the best defense against space.

Any modern day virus is a highly evolved form that took millions of years to evolve on an environment that includes microbes. They often have special means of inserting their unique genetic code into living cells.

Self replication is not a requirement for life.

I imagine an environment where all the pieces exist for replication, but self replication does not occur. A makes B, B makes C , and C makes A. But only locally is the mixture correct enough to maintain this loop with an input of energy.

It is possible, even likely...

[TheGatesofLogic]

The argument that viruses are not life because they require a host to replicate is foolish because by that very definition a large group of organisms we consider life without question would have to be excluded along the same premises. To explain: If you consider requiring a host for replication an exclusion for life then many parasites must now be considered non-lifeforms though they clearly demonstrate all other characteristics of life. Viruses, just like parasites, are a form of life that fill a niche. This niche may be so extremely parasitic that the lifeform does a marginal amount of the work in the process of its replication, but this replication would not be possible without the initial agent, and thus it acts in the same manner as all life.

[Aethon]

Here's one of my favorite articles on lifes' origin.

Did life begin with autocells?

http://www.space.com/23144-earth-life-autocells-gas-giants.html

Edited September 12, 2014 by Aethon

[magnemoe]

The argument that viruses are not life because they require a host to replicate is foolish because by that very definition a large group of organisms we consider life without question would have to be excluded along the same premises. To explain: If you consider requiring a host for replication an exclusion for life then many parasites must now be considered non-lifeforms though they clearly demonstrate all other characteristics of life. Viruses, just like parasites, are a form of life that fill a niche. This niche may be so extremely parasitic that the lifeform does a marginal amount of the work in the process of its replication, but this replication would not be possible without the initial agent, and thus it acts in the same manner as all life.

however an parasite has metabolism, an virus does not, metabolism is one of the requirements for life.

If virus are in how about computer viruses, how about prions who is an protein molecule who fools cells into making more copies of itself.

[vger]

however an parasite has metabolism, an virus does not, metabolism is one of the requirements for life.

...and our definition of life is just as 'concrete' as a scientific theory. They can end up being wrong. Somehow, I find the idea of virii NOT being life, more terrifying than the alternative.

[magnemoe]

...and our definition of life is just as 'concrete' as a scientific theory. They can end up being wrong. Somehow, I find the idea of virii NOT being life, more terrifying than the alternative.

Yes, however virus can not exist without other more advanced life.

If we drop the metabolism demand crystals become living creatures, they have an organized structure and grow, if an part separate it will grow independently and this process can be repeated.

[DJEN]

Wasn't it a fact already?

[Sky_walker]

Wasn't it a fact already?

There are many theories. Extraterrestrial source of life on Earth isn't the "fact" nor ever was.

...and our definition of life is just as 'concrete' as a scientific theory. They can end up being wrong. Somehow, I find the idea of virii NOT being life, more terrifying than the alternative.

It doesn't matter what's terrifying and what's not

And in that case - a definition of life from scientific point of view is already established. Homeostasis, organization, metabolism, growth, adaptation, response to stimuli, reproduction are how you recognize something is alive.

From scientific point of view - viruses are not forms of life but rather replicators (and: no, not the Stargate Replicators, "replicator" is a real scientific term that exists in a biology)

What people use in a common language is another matter. But by now we should know very well that people have an outstanding tendency to babble nonsense and not only "blur" terms but straight on change their meaning for no logical reason.

Edited September 12, 2014 by Sky_walker

[Camacha]

The argument that viruses are not life because they require a host to replicate is foolish because by that very definition a large group of organisms we consider life without question would have to be excluded along the same premises. To explain: If you consider requiring a host for replication an exclusion for life then many parasites must now be considered non-lifeforms though they clearly demonstrate all other characteristics of life. Viruses, just like parasites, are a form of life that fill a niche. This niche may be so extremely parasitic that the lifeform does a marginal amount of the work in the process of its replication, but this replication would not be possible without the initial agent, and thus it acts in the same manner as all life.

I have always felt that the definition of live is a bit contrived and the more we understand the various beings on this planet, the more that rings true. I am fairly certain that if and when we ever get to other planets with self replicating entities, we will need to revamp our definitions yet again. Life might very well turn out to be some arbitrary boundary with a huge greyscale landscape to put it in.

Edited September 12, 2014 by Camacha

[indroth]

And in that case - a definition of life from scientific point of view is already established. Homeostasis, organization, metabolism, growth, adaptation, response to stimuli, reproduction are how you recognize something is alive.

If you are saying all these are required, then I am, by definition, not alive because I don't have a girlfriend .

[KerikBalm]

I believe that it is possible, even likely, that life originated outside of earth.

I beleive it is possible, but not likely, due to the extreme unity of life at the basic level - implying that if life did get here from somewhere else, it only came once, and what came was a single species, and not some diverse microbial community like what you might expect.

This is not a rare position anymore in origin theories.

Panspermia is not an origin theory, it just takes the origin of life, and moves it somewhere else farther back in time.

I can imagine an environment where the objects that our now the contents of cells live in ecosystems.

Yea, people working on abiogenesis scenarios propose similar things.

Some microbial life is pretty complex, some is pretty simple.

As to the definition of life... you can make any set of criteria you want, it will be pretty arbitrary.

Modern molecular biology has no problem studying viruses as if they were any other organism.

Sure, we don't do metabolic studies on the virus particles (in general, some encapusulted viruses do continue to cary out some chemical reactions after leaving a cell) - but then there are many cases of cryptobiosis, in which an organism is metabolically inert. Perhaps you could consider a virus as something that lives inside cells, and enters a state of cryptobiosis while waiting for a suitable habitat to reproduce in.

[SorryDave]

I'd like your patience while I try and explain my position differently. This is a good forum for me to get some other views from all of you on the topic and I would really like to hear them.

I believe that the current attempt to find life in our solar system by looking for primitive microbes near water, will provide negative results. This would be true even though I believe that life is pervasive in the solar system and milky-way, and is either very ancient or created often.

On earth, this form of life evolved into microbes. Even a primitive microbe is a very complex system encased in a cell wall. I am arguing that microbes are a rare adaption of the form of life found everywhere else. They are the adaption to liquid water which is possibly toxic to a more common form of life.

The definition of life as currently used may not even apply here, as no examples now exist on earth. I believe that to exist everywhere, it would have to have a few properties.

1. This form of life would be hard to identify either because if current tool limitations or our method of searching.

2. It would be capable of replication and evolution, but does not have any parts that can self replicate.

3. It would exist as an open system, not an enclosed system. It could exist without cell walls.

4. It may not require chemical reaction speeds or short distances to operate successfully.

5. It may usually be dormant and for long periods of time.

6. You could pick up all the parts and place them down again randomly with a high chance of it still being able to replicate and evolve.

7. It would be composed of parts on the scale of cellular components, most maybe only dozens of amino acids long.

8. It could leave structures from its by products that resemble structures created by microbes or found in Martian meteorites.

9. It would tend towards increased complexity as it evolves. It would do so decreasing the entropy outside of the system of parts.

Under these assumptions, the creation of complex living things is far more statistically likely and may occur often. But the solution space is big enough that microbes themselves may be rare and possibly only developed on earth.

Is this possible? Likely?

Thanks

[KerikBalm]

I'd like your patience while I try and explain my position differently....

I believe that ....

This would be true even though I believe that ....

I believe that ....

...

Is this possible? Likely?

Sorry, too much "I believe" in there.

Space is empty... it is so so so empty.

Hydrogen atoms are flying around, but... they rarely even collide.

You're not going to get an acellular living system from a few hydogen atoms occasionally bumping into each other.

When you start getting to planets and moons, then you have some chances for interesting things to happen, especially on Mars, CeresEnceladus, Titan, etc.

We've been to the moon, what sort of self replicating system do you "believe" is there, and what evidence do you have for it?

If you can't find one on the moon, how do you expect to find one in a vacuum with a few hydrogen atoms per m3?

[SorryDave]

Sorry, too much "I believe"

Maybe I should have used "I theorize" to help you not be so sorry. I did not need to lead you to think I was presenting something I had objective evidence for.

I agree with every thing you said in your post and I appreciate your view.

I do believe that the replicating life I am suggesting would exist at places were organic compounds and amino acids may be found. This life would exist in comets and rich organic moons. It would exist in interstellar molecular clouds like the large one our sun is traveling through.

To be honest, any argument for exo-solar life must include a bit of belief. Methane generation on Mars may be geological or biological, I am really saying that if it is biological I "theorize" that it is not microbiological cells

[vger]

Yes, however virus can not exist without other more advanced life. If we drop the metabolism demand crystals become living creatures, they have an organized structure and grow, if an part separate it will grow independently and this process can be repeated.

Crystals don't 'evolve' into other varieties of crystals.

[Everten P.]

When I think of microbes in space I think of something like a coral reef built around the skeletons of the dead but maybe they aren't carbon based or maybe have found a way to generate ATP without the materials we have and have maybe created a planet sized ball of cells (being that they might be less advanced and came early in universal history). I think it would be awesome if there was a planet like that but alas, it would probably collapse over its own weight..

[Kryten]

When I think of microbes in space I think of something like a coral reef built around the skeletons of the dead but maybe they aren't carbon based or maybe have found a way to generate ATP without the materials we have and have maybe created a planet sized ball of cells (being that they might be less advanced and came early in universal history). I think it would be awesome if there was a planet like that but alas, it would probably collapse over its own weight..

And the material for this is supposed to come from where, exactly? Just because something is alive doesn't mean it can break conservation of mass.

[SorryDave]

...and have maybe created a planet sized ball of cells

What an interesting idea, say there is a 8 billion year old living "coral reef" orbiting a red dwarf in some ancient galaxy. The entire planet may have been evolving as it accumulates interstellar dust that slowly increases in heavier metals as the galaxy ages.

Not sure if it is possible, but still a cool and imaginative idea.

[Tommygun]

And the material for this is supposed to come from where, exactly? Just because something is alive doesn't mean it can break conservation of mass.

Comets,asteroids or particles caught up in solar wind?