Did life start from an autocatalyzing reaction with variadic products?

[bascule]

We'll probably never know, but it certainly seems like the most likely possibility!

 

(Also, excuse the abiogenesis thread in the evolution forum, but uhh, where else is this supposed to go?)

 

I really hadn't heard much regarding the issue of abiogenesis beyond the Miller/Urey experiment.

 

Then in The Ancestor's Tale (do you get the idea that I loved this book yet?) about experiments performed by Julius Rebek and his colleagues at the Scripps Institute in California. In it they combined amino adenosine and pentafluorophenyl ester with the autocatalyst amino adenosine triacid ester (AATE, which, being an autocatalyst, catalyzes the combination of the afforementioned chemicals into more amino adenosine triacid ester)

 

According to Dawkins:

 

Rebek and his team found a system in which more than one variant of the autocatalysed substance existed. Each variant catalysed the synthesis of itself, using its preferred variant of one of the ingredients. This raised the possibility of true competition in a population of entities showing true heredity, and an instructively rudimentary form of Darwinian selection.

 

Really neat stuff!

[Inquisitive7]

Well, this is very interesting. But hard to believe. Autocatalysis and polymerization will only give poly nucleotide(if at all this happens) made up of the same mono nucloetide Adenine. This is biologically inactive.

[DV8 2XL]

I like to think that exogenesis is the explanation for life's beginning on this planet. In fact I will go as far as to say I am a devout panspermia supporter, live has shown itself to be incredibly hardy, so the idea that some germ of it could survive the trip from another world is not that farfeched

[EverCurious]

I agree strongly with exogenesis as well. The chances of abiogenesis are astronomical especially in models such as primordial soup. The chance that natural chemical reactions can spontaneously create amino acids is more a figment of sci fi, than actual science, however they have adapted these models since these are the prevalent scientific theories on human genesis.

 

http://www.accessexcellence.org/WN/SUA02/primordial_soup.html

[aguy2]

Well, this is very interesting. But hard to believe. Autocatalysis and polymerization will only give poly nucleotide(if at all this happens) made up of the same mono nucloetide Adenine. This is biologically inactive.

Wouldn't it seem that if 'biological life' could so easily arise spontaneously in nature, it should arise even easier in the benign, supportive environment of the laboratory?

 

aguy2

[DV8 2XL]

Ok, let's say we do find life on Mars, and it found that it is made up of the standard amino acids. Would that that support exogenesis?

[aguy2]

Ok, let's say we do find life on Mars, and it found that it is made up of the standard amino acids. Would that that support exogenesis?

 

Wouldn't 'blaming' exogenesis for Terra's life form just be 'begging the question' as to how biological life arose?

 

aguy2

[DV8 2XL]

Yes, of course it shifts the problem up one level. However, if one accepts the possibility, we now have the possibility of life coming into spontaneous existence somewhere the entire universe, and not just this dirt ball - thus making it more likely

[aguy2]

Yes, of course it shifts the problem up one level. However, if one accepts the possibility, we now have the possibility of life coming into spontaneous existence somewhere the entire universe, and not just this dirt ball - thus making it more likely

 

Although I wouldn't discount the possibility of exogenesis in either direction, I personally think the concept just 'muddies the waters'. Besides, 3 1/2 billion years is a substantial chunk of the history of the universe. It would seem biological life couldn't arise anywhere else that much earlier.

 

aguy2

[Airmid]

Some nice reading:

The universe: a cryogenic habitat for microbial life

On the applicability of Darwinian principles

to chemical evolution that led to life

Controversies on the origin

of life

There's loads more stuff to find on the web, of course.

*edit* Found this great page just now: The RNA World: What's New

 

I'm not a firm supporter of the exogenesis theory, but I do think that the building blocks of life have been delivered from space. The main reason for that is that a huge amount of dust from space is still raining down on earth, even in these tranquil times. Estimates as high as 100 tons per day have been made!

So I'd say that when life will be found elsewhere, it would only support the theory that life's building blocks originate from space.

 

Airmid.

[bascule]

If you're a naturalist, then you most likely believe that abiogenesis happened somewhere. Exogenesis merely changes the location...