UV light may have sparked life on Earth

NewScientist.com ^ | May 28, 2003

[StupidQuestions]

UV light may have sparked life on Earth

18:18 28 May 03

NewScientist.com news service

Ultra-violet light, long thought to be an impediment to the early formation of long organic molecules, may in fact hold the key to the origin of life, according to a new study.

Intense UV rays from a young Sun bombarded the early Earth and were thought likely to destroy any exposed organic molecules. But a new mathematical model implies the radiation actually helped select out the molecular seeds of life.

The earliest life on Earth is widely thought to have been based on RNA, the chemical cousin of DNA. RNA is made of subunits called nucleotides, which link together to form long polymer chains.

Certain components of RNA absorb UV light and act as "protectors", thereby giving it a survival advantage over other molecules, says Armen Mulkidjanian. Mulkidjanian, a biophysicist at Osnabrück University in Germany, led the team that developed the theoretical model.

"Simple RNA molecules can evolve under certain conditions - this is a well-developed field. But the question left is: how do you get the first long enough RNA polymer?" says Mulkidjanian. "Our model offers some physically plausible explanation of how long RNA polymers could emerge."

"This paper is important because it attacks that crucial problem," says Michael Yarus, an RNA world expert at the University of Colorado at Boulder. "If this problem could really be solved in a way that people agreed on, the RNA world would become a fact rather than a speculation."

Peculiar properties

Life on Earth is thought to have evolved about 3.7 billion years ago, when there was no protective ozone layer encasing the planet and UV radiation was 100 times more intense than today.

The nucleotides that make up RNA have three components - a sugar, a phosphate and nitrogen-containing base. "And these bases have very peculiar properties of being extremely efficient at quenching UV light," says Mulkidjanian, protecting the sugar and phosphate components which form the spine of the chain.

The team fed data on the photochemistry of various organic molecules into a computer model designed to simulate the effects of UV light on stability. "The effect was very pronounced in RNA," he says. In the presence of strong UV light, RNA was much more likely to form long chains than other molecules. -more-

[StupidQuestions]

Yes, I am new to FR. I've enjoyed your discussions about evolution and creation for years and couldn't believe no one posted this earlier. I have no firm beliefs about how life began ... or even where life began. I do believe this research will prompt an interesting discussion however.

[PatrickHenry]

Ping. [This ping list is for the evolution side of evolution threads, and sometimes for other science topics. FReepmail me to be added or dropped.]

[Aric2000]

WOOHOO, now we can talk abiogenesis.

OK, Creos, here's your chance to talk about abiogenesis without getting wiped off the table for not understanding evolution.

THIS IS ABIOGENESIS, the thing you guys always want to talk about, so, LET'S TALK ABOUT IT!!!

[RightWhale]

Sagan was in the middle of the origin of life research. Not central, just there. He knew all the participants, went to their conferences, fed off them. Somewhere along the line he mentioned that given a bottle with the appropriate chemicals in it and a source of energy: heat, lightning, UV, extreme pressure, whatever provides a chemical kick, the complex chemicals of life form naturally. UV wavelengths are in the key energy range to have effect on chemical bonds. All this speculation was back around the time of the Viking Mars search-for-life landers. Early 70s.

[Aric2000]

For a minute I saw Satan, not Sagan, and thought geez, what the heck is up with rightwhale? LOL ;)

Yeah, I saw some of that stuff too, he talked about it in some of his books. Very interesting reading.

[NewYorker]

Bravo on a great first post!

[PatrickHenry]

We must put to bed the hoary notion that Louis Pasteur "proved" that life cannot arise from non-living material. Instead, what he disproved, was the very different idea floading around in his day, called Spontaneous Generation. Contrary to the endless lies found on varous creationist websites (hideous centers of ignorance and duplicity), Pasteur never proved (and never attempted to prove) anything about the ultimate origin of life on earth.

[UCANSEE2]

Finally they get it right.

The first life on earth started converting what chemicals were in the air and ground into the beginnings of our atmosphere. UV light had nothing to stop it. It stimulated chemical reactions which were part of the original creation of life.

Later, a new type of creature, very similar to the first, evolved which was able to put more into the atmosphere. It had a built-in engine or furnace and was more efficient. That first creature (cell) still exists, and the second one.... Well, them are us. We are made up of the second creatures.

[sam_paine]

"yikes" (Sam notes the impending barroom brawl and takes his beer to another room.) Bye!

[Aric2000]

Just watch through the glass, and of course toss a punch or 2 yourself, AFTER you put your beer down somewhere safe of course.

[js1138]

Pasteur never started a thread and watched for the spontaneous arrival of vermin.

[Michael_Michaelangelo]

Do chemicals have willpower and determination? Do they 'strive' to overcome obstacles? Are some chemicals heroes? Are some underachievers?

There are scientists all over the world who have said time and time again that the formation of even the building blocks of life is thermodynamically unfavorable and require a perceived selective advantage in order to form. I don't believe that you can apply natural selection to chemicals. So right out of the gate there are problems for the evolutionist.

And from a favorite website of mine:

In the pantheistic world view of the evolutionist, the fires of destruction are the wombs of life. Radiation, asteroids, collisions, and other devastating agents are our friends: they gave us the beautiful web of life we have today. Wonder how they feel about terrorism.

FRegards, MM

[Michael_Michaelangelo]

Okay! I have my super heavy duty flame-proof titanium body armor on, wolves, so have at it!

[c-b 1]

I descended from pond scum because UV light shown on pond scum? I have two questions. where did pond scum come from? Where did UV light come from?

[RightWhale]

Do chemicals have willpower and determination?

They obviously have some of the capability to sustain these soulful attributes.

[StupidQuestions]

In an Anthropic Universe, every aspect might be viewed as having the will and determination to produce life.

[js1138]

Your admirable thread has caught a fatal disease.

[Michael_Michaelangelo]

I have no problem with that notion. You are speaking of the Anthropic Principles?

Here's a quote I have saved from Paul C.W. Davies, Physicist and Professor of Natural Philosophy, University of Adelaide, AU.:

"The temptation to believe that the Universe is the product of some sort of design, a manifestation of subtle aesthetic and mathematical judgement, is overwhelming. The belief that there is "something behind it all" is one that I personally share with, I suspect, a majority of physicists" -1983

FRegards, MM

[bondserv]

Unanimated material.

Becomes.

Animated material.

The question regarding abiogenesis, does life require an animator or does nature have the capacity to animate?

[Ramius]

I'm not too sure how life began. I wasn't there when it happened.

I figure I'll find out someday. If I don't... that means there is nothing else, so it just doesn't matter anyway, does it?

I think I've achieved a certain peace on the subject.

Now, to pop some corn and kick up my feet... :-)