Ahhh, finally. The beginning of evolution!

[Randwolf]

From the New York Times, May 13, 2009:

Chemist Shows How RNA Can Be the Starting Point for Life

By NICHOLAS WADE
Published: May 13, 2009

An English chemist has found the hidden gateway to the RNA world, the chemical milieu from which the first forms of life are thought to have emerged on earth some 3.8 billion years ago.

...

He has solved a problem that for 20 years has thwarted researchers trying to understand the origin of life — how the building blocks of RNA, called nucleotides, could have spontaneously assembled themselves in the conditions of the primitive earth. The discovery, if correct, should set researchers on the right track to solving many other mysteries about the origin of life. It will also mean that for the first time a plausible explanation exists for how an information-carrying biological molecule could have emerged through natural processes from chemicals on the primitive earth

....


For more than 20 years researchers have been working on this problem. The building blocks of RNA, known as nucleotides, each consist of a chemical base, a sugar molecule called ribose and a phosphate group. Chemists quickly found plausible natural ways for each of these constituents to form from natural chemicals. But there was no natural way for them all to join together.

The spontaneous appearance of such nucleotides on the primitive earth “would have been a near miracle,” two leading researchers, Gerald Joyce and Leslie Orgel, wrote in 1999. Others were so despairing that they believed some other molecule must have preceded RNA and started looking for a pre-RNA world.

The miracle seems now to have been explained.

I wonder how far scientists will have to take the process before a few of the "intelligent design" types will begin scratching their collective heads, pondering the possibility of a "natural" origin for life... Hypothetically, would transforming inert chemicals to RNA to DNA to "animal" in the lab do it?

I suspect the anti evolutionary crowd will have fun, as many seem to object to evolution on the grounds that it does not explain abiogenisis (although the two are totally unrelated)

(Don't worry, there was still plenty to do to keep your gods busy...)

Comments?

 

[granpa]

couldnt rna itself have evolved from something simpler?

 

[Randwolf]

couldnt rna itself have evolved from something simpler?

Quite probable. Again, from the article:

for the first time a plausible explanation exists for how an information-carrying biological molecule [nucleotides / RNA] could have emerged through natural processes from chemicals on the primitive earth.

I don't believe the author is implying that we can "make our own dirt", but it's looking more and more like we are able to assemble existing clay into "life".

 

[S.A.M.]

Does it matter? When you finally slice through the baloney, this is what you get (for now)

 

[Hercules Rockefeller]

couldnt rna itself have evolved from something simpler?

Yes. RNA formed from simpler molecules, viz ribose sugars and cyclic nitrogen-containing molecules (purines and pyrimidines). Such precursor molecules are thought to have been common in the newly-formed Earth. We even find them in extraterrestrial sources.

 

[Hercules Rockefeller]

Mod note: Nonsense attempts to criticize the scientific method have been moved to a thread in the Pseudoscience forum. Please restrict discussion here to actual scientific inquiry.

 

[leopold]

the discovery of the origins of life have always been "right around the corner" ever since the miller-urey experiment some 50 years ago.
unfortunately none of them have succeeded.
i suspect this will fit the norm.

 

[S.A.M.]

I strongly doubt that. I am pretty sure that sooner rather than later we will stumble on to the "how" of it. Whether we can answer the "why" is questionable.

 

[leopold]

I strongly doubt that. I am pretty sure that sooner rather than later we will stumble on to the "how" of it.

i'm not so sure. catalytic chemistry is an exact science for known catalysts, trial and error for others.

Whether we can answer the "why" is questionable.

is the "why" important?

 

[cosmictraveler]

Not trying to be funny but where did RNA come from to begin with? :shrug:

 

[leopold]

Not trying to be funny but where did RNA come from to begin with? :shrug:

no, it's not funny, it's a valid question.
apparently RNA came from a racemic mixture of amino acids.
but that can't be true unless some type of catalyst selected for handedness.

 

[Hercules Rockefeller]

apparently RNA came from a racemic mixture of amino acids.

Apparently rubbish. Do don’t have the slightest idea what you’re talking about. Amino acids are the monomer units of peptides/proteins, not nucleic acids like RNA and DNA.

Just please stop interjecting with your atrocious misunderstandings of this subject.

 

[Hercules Rockefeller]

Not trying to be funny but where did RNA come from to begin with? :shrug:

As indicated above, RNA came about through the interaction of ribose, phosphate and purine/pyrimidine molecules. Exactly how I don’t know; I’m not sure anyone knows.

But once they did they created an early RNA molecule that had a number of key properties. It could both store information like DNA and act as an enzyme, properties that may have supported cellular or pre-cellular life. The key was developing the ability to catalyse its own replication. RNA-based catalysis and information storage is the first step in the evolution of cellular life according to the ‘RNA World Hypothesis’.

 

[S.A.M.]

I think he's referring to the chirality of amino acids and the L-isomer being the naturally prevalent one in proteins.

 

[S.A.M.]

i'm not so sure. catalytic chemistry is an exact science for known catalysts, trial and error for others.

Not aware of what you are referring to but in any case, it would be work in progress.

is the "why" important?

To me, yes. I'd be interested in why a combination of abiotic molecules leads to the phenomenon of consciousness. Just mixing them up and getting the "building blocks" of life is interesting, but it doesn't reveal to me why these blocks get together and lead to a person with opinions on art, for instance.

 

[Enmos]

To me, yes. I'd be interested in why a combination of abiotic molecules leads to the phenomenon of consciousness. Just mixing them up and getting the "building blocks" of life is interesting, but it doesn't reveal to me why these blocks get together and lead to a person with opinions on art, for instance.

There is no why, only how.

 

[leopold]

To me, yes. I'd be interested in why a combination of abiotic molecules leads to the phenomenon of consciousness.

well yeah, consciousness is another thorn to contend with.
this is the reason i stated in the other thread "the more i think about this the messier it gets".

 

[S.A.M.]

There is no why, only how.

Except that our belief in causality is the reason we all study science.

 

[Enmos]

Except that our belief in causality is the reason we all study science.

The self is an illusion.

 

[S.A.M.]

And this is the biology forum. Hercules has already split the thread for pseudoscience.