Neil deGrasse Tyson: "Is DNA Inevitable as the Life Code for the Universe?"

Neil deGrasse Tyson believes that BIG question of the 21st century is will we discover life somewhere other than on Earth? He views it as an "unimpeachable first goal" in our exploration of the cosmos.

And what most fascinating is the question of whether that life has DNA. It's  fascinating, Tyson says, because either DNA is inevitable as the foundation for the coding of life, or life started with DNA in only one place in the solar system and then spread among the livable habitats through panspermia. Microbial life can land on and seed another planet, thereby not requiring that you have to create life from scratch multiple times and in multiple places.

Another totally intriguing possibility, one of many that deGrasse Tyson Director of the Hayden Planetarium at the American Museum of Natural History and host PBS's NOVA scienceNOW., describes in Origins: Fourteen Billion Years of Cosmic Evolution, is that there is life that has encoding that has nothing to do with DNA.

It is the relentless shifting and mutating of DNA, says Dennis Overbye in a brilliant essay in The New York Times, that generates the raw material for evolution to act on and ensures the success of life on Earth (and perhaps beyond). Dr.Paul Davies co-director of the Arizona State University Cosmology Initiative said that he had been encouraged by the discovery a few years ago "that some sections of junk DNA seem to be markedly resistant to change, and have remained identical in humans, rats, mice, chickens and dogs for at least 300 million years."

But Dr. Gill Bejerano, Assistant Professor of Developmental Biology and of Computer
Science at Stanford, one of the discoverers of these “ultraconserved” strings of the genome, said that many of them had turned out to be playing important command and control functions.

“Why they need to be so conserved remains a mystery,” Berjerano said, noting that even regular genes with known functions undergo more change over time. Most junk bits of DNA that neither help nor annoy an organism mutate even more rapidly, Overbye points out.

What your quess: Is the DNA the cosmic code for life in the universe, or is it possible that there's are alien, unknown foundations? At the Galaxy, we place our chips on DNA.

Posted by Casey Kazan.

http://www.pbs.org/wgbh/nova/origins/tyson.html
http://www.nytimes.com/2007/06/26/science/26DNA.html?_r=2&oref=login&oref=login

Image Credit: Copyright Jimmy Turrell

The new season for NOVA scienceNOW hosted by Neil deGrasse Tyson starts June 30th at 9PM ET/PT on PBS.

Comments

[Bob]

Awesome! You totally lifted that graphic on the NYT website then slapped some ads next to it. Profit off someone else's work=great business model.

[Skinny]

I profoundly disagree with this. Nothing makes DNA special - the A,T,C,G code is arbitrary. A good parallel is language: there is nothing in the letter "a" that suggests an "ah" sound fundamentally, and thus languages all over the world have different letters for the "ah" sound.

I would not expect to EVER find DNA on another planet. What I would expect is to find a different replicator that can store heritable information, that can copy itself, and that has a very low error rate but one that is not zero. To expect that two, independent lineages will hit upon the same language is tantamount to expecting that when the Spaniards first discovered the Mayans, they both talked to each other in English.

[Ray Ray]

Good point, Bob. However ... I think Dr. Tyson's point is not that DNA evolved simulatneously on Earth and on other planets. The suspicion is that, since we now know that life can survive the vacuum of space, and since we know our planet has been bombarded with ice balls, meteors, planets, etc .... what if the basic building blocks of life, once they evolved somewhere, are being spread around the cosmos. Why re-invent the wheel? And I don't think he's saying he believes it's one way or the other. He's saying it's a major, valid, very important question yet to be answered. The theory of Panspermia is not new, and it's gaining more and more acceptance and respect as the science involved progresses.

[Ray Ray]

Woops! ... I meant "Skinny" not "Bob". Sorry Skinny and Bob.

[EvilCosmicMonkeyfrom Knoxville]

If DNA itself doesn't exist in other locales, then maybe there's something analogous to it, in the case life that may not be carbon - based. But my money would be on DNA existing anywhere, even in the most inhospitable locations.

[Barrie O'Leary]

Ever since Weigel proposed his theory of continental drift in 1927, it was viewed suspiciously, even forty years later. But then scientific view change and for the last forty years it has been viewed as one of the holy grails of geology. The idea of rotating orbits of planets was proposed thirty years ago but still has to be viewed with the now available outer space proof that it originally lacked. These things take time.

But what proposal for intergalactic transport is considered likely? Galactic collisions?

[bitirim]

thank you

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