How Did Life On This Planet Begin?
 

To go along with the "Do You Believe in Evolution?" Thread.

link

Give reasons for your belief.

I chose life arose from nothing, because it is science's best guess so far.

Probably wet and screaming.

Not to sound like a creationist ;), but wouldn't Creation or Abiogenesis(or another theory) be needed to lead to Panspermia? I don't consider Panspermia to be a starting point.

I always thought that Life began with $2000 and a car...

I wouldn't call it a belief but an acceptance that, on the evidence available so far, life evolved from non-life.

Good point...I'll amend by saying "Life on this planet" rather than life in general.

Interesting. What proof?

Proof? Whatchoo talkin' bout Willis?

You may have missed the memo, but none of this stuff has any proof.

I'm not a biologist but I accept the opinion of those with the relevant knowledge that that is so and I see no evidence whatsoever for the others.

What biologist has observed or reproduced Abiogenesis in the lab?

I have no idea, but I voted for life being seeded from space, because that what Star Trek says.

Actually, if that is the case, that still leads open the question of how that life began. While firmly believing life on earth evolved from pretty basic lifeforms, I really don't have any problem with the idea that someone else provided the starting push.

Since the process would likely take millions of years, of course the answer is no one.

I really can't pick one, if I had to I'd probably lean towards Panspermia for Earth and Abiogenesis in general. Not enough evidence though.

I don't believe in creation, it's just too damn simplistic, there is no such thing as a divine being. Now I could accept the possibilty(emphasis on possibility) of a being having the ability to create life, but that being would need to come from somewhere as well.

They have formed amino acids (the building blocks of life) by simulating the conditions that were present from early on in Earth's existence.

I presume it comes from the fossil record as no biologist was presumably around at the time :)

But you miss the point: as there is absolutely no evidence for the other suggestions whatsoever then the "out-of-non-life" option is the acceptable one - it is the best option at this point in time.

Even in a lab under controlled conditions?

There's no hard evidence supporting Abiogenesis either. So I'm assuming people are selecting choices to fit their world views (i.e., I believe there is no God(s), therefore life just happened).

No mainstream scientist believes we can pinpoint the exact moment life comes from non-life and/or what conditions make it occur. The theories presume a long series of changes and conditions which make the change from non-life possible. That is not possible to do in any lab setting at the present time.

I believe they have set up experiments along these lines but I don't know what the outcome was.

Interesting choice of words.

I suppose, since he seems to be pro-evolution ;).

Creation. The world and life is too complex for simple chance. Mathematically its very unlikely that all things arose by chance. I also believe that everything evolved and continues to do so. However, I am unsure as to where that process began for humans. I definetely do not believe we evolved from a single cell organism. That being said, I am a Christian, not a literalist Christian (in other words, I do not believe the Bible was written literally in areas.)

I think you'll find there is a fossil record.


I'm sure the world view comes into it.


Not at all. I don't believe "there is no god" not do I believe there is. I don't know. Nor, in my opinion does anyone else. There is no evidence for god so he/she/it doesn't come into it.

The only evidence we have points to life springing from non-life - maybe non-life isn't as different from life as you think.

Heh, to early. I meant to say Abiogenesis in my earlier post, not creation. Not surprisingly everyone's opinion on this will follow their religious beliefs. Not much to debate, either a God exists and created life, or a God doesn't exist and you accept the idea that we may just not know.

Not knowing means just that, it does not mean the simplest explanation must be true.

While I believe in life coming from non-life, I find your arguments a little odd, Mac. I don't know how the "fossil record" could ever establish this theory in anyway. If life came from non-life, there would be no fossilization of the initially created single cell organisms.

Mathematically it's very unlikely that someone wins the lottery, but they do. ;)

Not sure how you quantify the chances of something, given an infinite amount of time and space.

I did hesitate when I used the word and I'm not sure it's the right one. But I don't have a better one.

Why not?

putting a trout option in your poll invalidates it to be honest :)

Single cell organisms don't produce fossils that I know of and I don't believe any fossils from that long ago have been discovered because of the various changes the Earth has undergone. Either way, fossils just show at some point life occurred. They don't do anything to explain the underlying cause.

This is the thing that I don't get. People see a world full of complex and varied life forms, so they try to explain how all these life forms came into being. Cleary, it's hard to explain. So what they do is develop a belief in the existence of an even more complex and hard-to-explain all-knowing, all-powerful being who must have created all of the complexity that they were having a hard time explaining in the first place. Isn't an all-knowing, all-powerful being even more difficult to explain than the life forms wee see on Earth? Isn't it even more mathematically unlikely? :confused:

Abiogenesis, because divinity, extraterrestrial seeding, and three-billion year old trout require the existence of something outside our current verifiable knowledge. Abiogenesis, however unlikely it may be to occur at any one given moment in time (however, it perhaps only had to happen once in a bilion years or so), is conceivable within our current understanding.

Has nobody heard of the Miller-Urey experiments?

http://www.chem.duke.edu/~jds/cruise_chem/Exobiology/miller.html work safe, from the Duke Chemistry website. I'm not saying it's proof or anything, but they have tried to reproduce the early conditions in laboratories and found the building blocks of life could be created from gasses and electricity (simulating the harsh conditions on the primitive Earth).

Like I said not proof, but they have run experiments on abiogenesis.

This has no scientific basis at all. There are fossils of all sorts of stuff that never lived. It's just that fossils of old rocks or dirt aren't all that interesting, so we don't spend a lot of time collecting them.

Tell me if I'm wrong, but my understanding is that fossils are just the "shadow" of bones left in rock. A single cell or even multi-cell organism without even a basic form cannot leave a fossil record.

Not true. There are fossils of leaves, fossils of simple organisms with no bones. Basically, if something can be encased in silt or mud, it can become fossilized.

There was the short-lived euphoria over Miller’s prebiotic soup experiments in the 1950’s. Boiling and electrically sparking a mixture of methane, ammonia, hydrogen and water produced some basic amino acids. But follow-up work only illuminated new barriers between complex chemicals and the simplest conceivable life. Finding the building blocks does not solve the problem any more than finding stones could explain the naturalistic production of an ancient cathedral.

Also as the article you linked points out..."There has been a recent wave of skepticism concerning Miller's experiment because it is now believed that the early earth's atmosphere did not contain predominantly reductant molecules. Another objection is that this experiment required a tremendous amount of energy. While it is believed lightning storms were extremely common on the primitive Earth, they were not continuous as the Miller/Urey experiment portrayed. Thus it has been argued that while amino acids and other organic compounds may have been formed, they would not have been formed in the amounts which this experiment produced."

Looking at google, I am apparently wrong. What would a single cell fossil look like? That seems amazing to me. It would decay completely and just leave an empty space that is extremely small. How would you know it was a single cell fossil? Fascinating.

As I said I'm not a biologist and don't pretend to know the fossel record - I accept the opinion of those that are experts. What we do have is that the earliest fossils are of the simplest kind - presumably single cell life. Prior to that we have nothing but non-life. This implies that either life came from this or something (a creator) introduced it at this point.

But there is no evidence whatsoever for a creator.

So I'm left with the move from non-life to life. As I said maybe non-life isn't that different from life - from complex molecules to slightly more complex molecules.

This argument reminds me of my 5-year old daughter's explanation when my newly laid lawn started to grow mushrooms. When I said I didn't know why she told me it was the fairies sheltering from the rain.

Now her explanation has reason behind it. The major problem with it was that there was no evidence for the fairies.

In the same way the argument for a creation of the life fails because it requires a creator and there is no evidence for such.

Life coming from outer space stands a better chance in my view.

Webster's definition of "fossil":

"a remnant, impression, or trace of an organism of past geologic ages that has been preserved in the Earth's crust."

So only living things leave fossils.

Great point.

To those of you who disagree with "Life comes from nothing" - how did God come into being?

SuperGod?

No. There's no reason why anything with structure shouldn't leave a fossil. As long as it can leave an impression in the mud then you can have a fossil. I presume there's little interest in non-life fossils.

I'm going with Joe Pesci.

Fine. Semantics. There are still old rocks encased in newer rocks that are for all purposes fossils of rocks from long ago. Your point proves nothing of substance in this thread.

Actually there is more evidence, albeit anecdotal, to support fairies than Abiogenesis. Many people have claimed to see, interact, and in some cases, photograph fairies. As far as I know, no one has ever observed or been able to reproduce Abiogenesis. Not for lack of trying either. Science has been trying to produce Abiogenesis in the lab since the mid 1920s.

That's right. The fossil record moves from only non-life fossils to the simplest life fossils. The implication is that the second comes from the first.

It must be remembered that there is nothing about the molecular structure of life forms that doesn't exist in the molecular structure of non-life forms. The first is merely more complex than the second.

Nobody has been able to reproduce God in a lab either. I guess there is more evidence for fairies than God.