A thought

[mosaicmouse]

Of course most of the molecules denature, but there are still enough left to be found in landed meteors.

It's a game of chance. Amino acids and nucleotides aren't sufficient to create life. A living organism also must have a degree of compartimentalisation: a cell membrane, so it can win free energy from it's surroundings.

However there are models for membrane-less "living" systems, in which a molecule randomly gains the property of self-replication, or the replication of another molecule, which in his turn can copy the original in a "one hand washes the other" fashion. (the latter seems more improbable, but it doesn't require 2 of the same molecules)

A good candidate is the RNA molecule (composed of nucleotides). It can act as an information carrier, but also as an enzyme (ribozyme) capable of processing other molecules in various ways.

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

 

[ararat]

what I always found a bit objectionable of the panspermia idea was that the stuff that supposedly landed on our earth must have taken form somewhere else and the problem is still the same how inanimate matter can become life. or do people consider this idea to be more likely solely because of the gain in time that this would allow?

 

[IJesusChrist]

When a meteor contains amino acids or nucleotides it doesn't mean they are bound to only the surface.

As is often the case, meteorites and asteroids are very porous objects, and the possibility that some of the organic material [organic does not mean biological] escapes the heat is pretty reasonable.

Life seems alien to me. Everything about it is misunderstood. If we fully realized the complexity of the human body on a continual basis I don't know how I would function. It is so immaculate, so intricate, so complex yet organized its amazing! And yet it was/is made by pure probability and chance.

The theory of life originating from places other than Earth is simply the "blame it on someone else" paradigm. We can't explain it, so we push it somewhere else. There have been plenty of studies that have made simple organic molecules in experiments using archaic conditions and most people understand that these molecules, under heat, pressure, and sun light have very interesting possibilities in more complex rearrangements.

I believe the capability of making a simple cell is fairly easy, however the machinery to replicate itself, such as RNA and DNA is very improbable. Immensely improbable, in fact.

I think had life not originated when it did, out of some very odd, freak conditions somewhere, it may have never happened. What I mean by that is, the origin of life as we know it on this planet is so improbable, that had that one event not happened that allowed the replication of a single cell to form, it would not have happened again.

What that one event is could be anything from a volcanic explosion, a meteor hitting the ocean, a ocean vent spewing out something unlikely, or many simultaneous events occurring at once giving rise to once-in-a-universe type of situation. I think we will answer a lot of our questions if we discover life within our solar system. They are finding oceans, both salty and fresh within the moons and planets of our neighborhood.

 

[mosaicmouse]

IJC, no one knows how probable the emergence of life is.

Earth formed about 4.54 billion years ago.
Prokaryotic cells existed about 3.8 billion years ago.

Seems to me it didn't take that long...

I believe the capability of making a simple cell is fairly easy, however the machinery to replicate itself, such as RNA and DNA is very improbable. Immensely improbable, in fact.

How about virusses?

If you read the RNA-world wiki, you'd see that in a loaboratory they have produced RNA that can replicate other RNA molecules. This copy-machine was only 165 nucleotides long. And there were several different molecules with the same property.

No imagine an RNA puddle sitting there for a couple million years until there are 2 of these copy machines that encounter each other. Doesn't seem that far fetched to me.

 

[IJesusChrist]

Earth formed 4.5 billion years.
Prokaryotes formed 3.8 billion.

Yes - but don't you see something a bit odd - no other life forms came about during that time period? It may perhaps be that we had two parallels, like viruses, or something like mitochondria forming along with our bacterial ancestors, but it isn't clear. If this isn't the case why didn't life form twice?

I understand that once "our" life - that which we are familiar with now - populated the planet, it would be increasingly difficult for other life to form, simply due to presence of hungry bacteria or bacteria-phages or the likes.

But I digress, I suppose we really don't know enough about that time period to say anything conclusive, so I'll leave conjecture out. I also don't know where you got your wiki-rna article, you should link me. Synthesizing RNA in a lab may be a bit different than it's formation in nature; did they use natural conditions?

 

[ophiuchus]

it's linked two of his posts back.

i just think that with the degree of probability of organic compounds being transportable through space and coming to earth, and the generally accepted notion that the early earth could have fostered, if not produced organic compounds of it's own, in combination with the principle of rna "wanting" to self replicate, that it would be unlikely to prove anything other than the universe being extremely fertile place that, by design, fosters the formation of what we call "life".

 

[goldwine119]

I don’t have any children. The first time I gave it any thought at all, I think, was around 1972. When I found out that the global population at that point was a whopping 3.5 to 4 billion people, I thought to myself, even then, “No way, I’m not bringing anyone else into this situation!” and now it’s about 7 billion. Why do people of any age who have half a brain even consider having children at this point? Is it just some instinctive mammalian urge to reproduce that over rules common sense? Are we just going to go on with this until there isn’t room for any other species besides ours to exist (aside from insects and microscopic life)? At what point will people finally wake the fuck up to the fact that over population is at the root of almost every problem currently facing us as a species? Personally, I think the threshold has already been crossed, and our only hope as a species is some sort of catastrophic reduction in population, which hopefully does not destroy the technological and scientific knowledge we have accumulated. Just my opinion. Like I said, I don't have any children. I'm also over fifty and I've had a great life, so to the rest of you I would just say....

 

[IJesusChrist]

The thing is, at least with me, that I feel robbed of the possibility of having a child due to the population.

I want a child, and I know my child (well with a certain probability) would be sustainable in ideological principles and overall I think would contribute more than s/he takes.

But now, I am in a sea of the same people saying the same thing. It is instinctual. It should be a given that you can have a child, after all, that is the scientific ... "purpose" ... we are here. We want to pro-create.

 

[IJesusChrist]

no, just a general statement...

 

[Crimzen]

yep its a spam bot designed to not be deleted by posting something relevant to the thread
done it in a few other threads too

 

[Guhyayoga]

Sticki had it right.

Overpopulation is a myth.

There are enough resources on this planet to support 20 billion people or more.

What we have is not a shortage of resources, nor overpopulation.

We have catastrophic mismanagement of resources. Once we get our act together I say forward ho! to population growth.

Also, we need people with developed consciousnesses bringing children into the world, not to be self-indulgent consumers, but aware contributors.

People who will help fix the mismanagement of resources.

 

[Crimzen]

This is true
but considering our terrible mismanagement of resources, relatively we are overpopulated
if we were to manage out resources more efficiently then we would be in a golden age but unfortunately we are still stuck with those who are absolutely greedy and therefore are stuck with a shit economy