the miller urey experiment

[AARONDISNEY]

This is just a general question, sorry if the answer is simple, I'm kind of new to this stuff.

 

When Miller and Urey tried to create life in the lab, it is often said that they did not use oxygen, but one of the gases they used was water vapor. Would water vapor not include oxygen, or would the oxygen not oxidize their product since it was tied to the hydrogen.

 

If someone could explain this to me in some simple language I would appreciate it very much, thank you.

[Mr Skeptic]

You need oxygen to breathe. Breathing water just won't do it. Water contains oxygen, as do carbon dioxide, carbon monoxide, rust, sugars, proteins, etc, etc. These are all different chemicals, but the oxygen they have is already bound to something. When people say oxygen, they are usually referring to O₂. Even O₃, ozone, wouldn't count, even though it is composed only of oxygen molecules.

[CharonY]

Precisely. A water molecule (H2O) has different properties than oxygen (O2), regardless of their respecitive state (be it solid, liquid or gaseous).

Oxygen was introduced much later due to biological activity into the atmosphere.

[AARONDISNEY]

Thanks guys. So oxygen bound to hydrogen would be completely different than free oxygen.

 

It seems like it would be impossible for life to start from non-living material then, if it couldn't start with oxygen (it would oxidize) or without oxygen (as has been demonstrated by their failed experiment) - Do you think there's any way that a scientist could actually make this happen?

 

I personally think there had to be a Creator, it seems this origin of life subject has the scientists checkmated and they don't want to give up the fight.

[iNow]

Do you think there's any way that a scientist could actually make this happen?

They already have. No need for a belief some imaginary creator.

 

 

Here's a fun video which is easy to follow:

http://www.youtube.com/watch?v=ozbFerzjkz4

 

 

 

If you prefer reading, this is an absolute must:

http://www.theharbinger.org/articles/rel_sci/fox.html

[Mr Skeptic]

There are plenty of anaerobic life forms, which don't need oxygen and are usually killed by oxygen. Seems like bad design given that oxygen makes up 20% of our atmosphere, no?

[CharonY]

Yupp. It is a misconception that all organisms require oxygen. The first ones did not and in fact the occurence of oxygen (due to photosynthetic bacteria) led to one (if not the) largest extinction of (bacterial) species in the early history of earth.

 

Oxygen is but only one of many terminal electron acceptors.

[Realitycheck]

As Charon implied, the reason why Miller and Urey set up the experiment the way that they did, without pure oxygen, was to mimic conditions at the onset of this type of activity on the planet. Gradually, these chemicals developed into more and more complex chemicals, until conditions were just right for the formation of a very simple cell-like organism that was capable of replicating itself. Time is really the essential key, as it took 1 BILLION years to form this very simple organism, something which probably started out quite differently than the cyanobacteria which it evolved into to provide so much oxygen to the earth's atmosphere. Measure that against the mere 300 million years that it took multi-celled organisms to evolve into dinosaurs and another 250 million years to evolve into intelligent man.

[macbeth91]

Urey and Miller's experiment wasn't a failure, like AARONDISNEY said. their aim was to test the theory that organic molecules could be made in the prehistoric conditions of earth. this theory was developed earlier (by a few guys who's names slip my mind)...and until Urey and Miller came along, there was no proof/test. this conflicted the concept of panspermia (the idea that comets carried life to earth), and showed that amino acids could be made...and we all know amino acids to be the building blocks of life. besides that, and to answer the original question, there was know free oxygen in the atmosphere. when water eveporates it is a change in physical state. it is not a chemical reaction like electrolysis, and thus the oxygen was still attached to other hydrogen atoms. we need oxygen in it's free, diatomic state....not joined to anything else.

[iNow]

Aaron,

 

I saw this story today, and thought of your thread here. I hope you find this information interesting. Enjoy.

 

 

http://environment.newscientist.com/article/dn14966-volcanic-lightning-may-have-sparked-life-on-earth.html

One of the most famous experiments of all time has just been found to have been even more successful than anyone realised. The Miller-Urey spark flask experiment could hold the key to the origin of life on Earth.

 

Jeffrey Bada of the Scripps Institution of Oceanography in California and colleagues re-analysed the original 50-year-old samples left by Stanley Miller ... <

more at the link

>

 

 

 

 

One criticism of Miller's experiment is that he got the atmosphere of early Earth slightly wrong. The new discoveries could give it a second life. The conditions in Miller's flasks may not replicate the ones covering the entire surface of Earth, but they could have been found in small regions around the planet. According to Bada, Miller's gases could have been spat out by the many volcanoes that dotted the planet at the time.

 

All that would then be needed is electricity – and many large volcanic eruptions are accompanied by spectacular lightning. This was the case, for instance, when the Chaitén volcano in Chile erupted for the first time in 9000 years in May 2008 (see image, right).

 

"Instead of Darwin's warm little pond being the entire ocean, the warm little pond could have consisted of volcanic island tide pools and lagoons," says Bada.

 

 

 

 

 

They also had a short interview-type story at the link which is available on YouTube at the following:

 

 

 

In addition to the story above, Pharyngula did a post on it this morning. You can read that here:

http://scienceblogs.com/pharyngula/2008/10/old_scientists_never_clean_out.php