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Craig Venter Wants To Rebuild Martian Life In Earth Lab
Hugh Pickens writes "Karen Kaplan reports in the LA Times that Craig Venter is making plans to send a DNA sequencer to Mars. Assuming there is DNA to be found on the Red Planet – a big assumption, to be sure – the sequencer will decode its DNA, beam it back to Earth, put those genetic instructions into a cell and then boot up a Martian life form in a biosecure lab. Venter's 'biological teleporter' (as he dubbed it) would dig under the surface for samples to sequence. If they find anything, 'it would take only 4.3 minutes to get the Martians back to Earth,' says Venter, founder of Celera Genomics and the Institute for Genomic Research (TIGR). 'Now we can rebuild the Martians in a P4 spacesuit lab.' It may sound far-fetched, but the notion of equipping a future Mars rover to sequence the DNA isn't so crazy, and Venter isn't the only one looking for Martian DNA. MIT research scientist Christopher Carr is part of a group that's 'building a a miniature RNA/DNA sequencer to search for life beyond Earth,' according to the MIT website 'The Search for Extra-Terrestrial Genomes.' SETG will test the hypothesis that life on Mars, if it exists, shares a common ancestor with life on Earth. Carr told Tech Review that one of the biggest challenges is shrinking Ion Torrent's 30-kilogram machine down to a mere 3 kg – light enough to fit on a Mars rover."
Except the half-life of DNA is only 521 years. I don't know, but I would be highly skeptical of there having been life on the planet within that time period.
That's the big question - is it a coincidence? It's entirely possible that, just as the CNO cycle is a common method of fusion in stars, that DNA, RNA or close analogues (eg Si or As based) are common ways of producing self-replicating molecules. We've only got a single data point, any speculation on the molecular basis of ET life is just that, pure speculation, until we have a second point.
Please consider this account deleted, I just can't be bothered with the spam anymore.
Morten et al recently examined DNA in 158 bone fossils and determined the half-life of DNA to be 521 years in their sample. Even if Martian DNA functioned in the same manner, the idea that environmental conditions on Mars were suitable to sustain life as late as the year 1491 is ludicrous. http://rspb.royalsocietypublishing.org/content/early/2012/10/05/rspb.2012.1745.abstract?sid=abb89d94-00f1-431b-8863-c62996e35478
Having the exact stream of bytes of an ARM program will do you no good if you place it in an x86 CPU and expect it to run. Or even one variant of an ARM to another with different I/O, timers, etc. Simply transferring entire genomes between far distant organisms on Earth won't work. When the organisms are distant enough from each other there is variance in the code itself (stop codons, etc) and the machinery the specific code will be manipulating must be there to be controlled. Ribosomes vary, organelles certainly vary. In fact it's rather presumptive of us to assume the genetic mechanism must be DNA or RNA when there are probably all sorts of other mechanisms that would work suitably. Even presuming life had a common origin and there was some event that seeded Mars with Earth bacteria (or the other way around) a few billion years ago, doesn't mean there is the slightest chance it's in any way compatible with anything that could be found on Earth today. Very different environments will select for very implementations over those billions of years.
Yeah, with little if any magnetic field and barely any atmosphere so tons of radiation reaching the surface, and an unlikely chance that alien life has DNA as we know it, that sounds like a great idea.
It's not as flexible as you might think. We have reason to believe that ribose and the nucleotides are inherently more common in the universe, and the chemical behaviour of DNA and RNA both are extremely convenient and flexible by comparison with the alternatives we've synthesized. These are artefacts of quantum physics, universal constants, and how stars die. If the universe is an experiment designed to see what conditions cause life to arise, current astrophysics would posit that we are about as standard as it gets.
The same goes for enclosing the self-replicating material in a membrane made out of lipids: some propose that the presence of lipids was required for life to start in the first place. Without some kind of solvent-filled (i.e. water-filled or ammonia-filled) cell, the only way to protect sensitive inner workings from the outside is by having a thick layer of solid material with no flexibility, which is extremely bad for evolution.
Moreover, a lot of the theories about life on Mars depend on it either (a) being cognate with life on Earth (perhaps even the cradle), or (b) having a comparable biosphere to Earth's billions of years ago. And that's without considering panspermia. Given that it's from roughly the same mix of nebula as Earth, we've already got a lot in common.
That all being said, however, Venter is once again vastly overambitious. 'Booting up' synthetic chromosomes only works in sufficiently similar chassis, and for very simple organisms (true Martian life would be radically different in terms of cell configuration and structure); an environmental sample of Ion Torrent reads is most likely not sufficient to clearly resolve specific genomes; any life on Mars is not likely to be near the surface within a rover's reach; any life near the rover's reach is probably a Terran contaminant. If anything comes out of this, it will be a new upper bound on "how many people can roll their eyes at Craig Venter."
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
We're not that blind. We can study the chemical fitness of different atoms by looking at the amount of energy it takes them to undergo various chemical reactions versus other counterparts. Silicon, despite science fiction's love for it, is an extremely inflexible atom: it can't form bonds with any of the major non-metals we use (oxygen, nitrogen, sulphur, and phosphorus), and it can't form bonds with a number of the coordinating metal ions we use, either. You may say "oh, well, it can just use other stuff and have a big ol' alternative party," but there aren't many alternatives. Carbon is useful not only because it forms many bonds, but because it can form them with these atoms in particular, which are biochemically equivalent to tools. No tools, no catalyst, no enzyme, no metabolism, no life.
If I were a god-fearing scientist, I would tell you that we live in an experiment designed to see how frequently RNA, DNA, and polypeptide-based life evolves. (And I'm starting to worry I may eventually become one, simply because of how perfectly our biochemistry falls out of the periodic table. If there is an alternative way of doing things, it's not something obvious like swapping out one chemical.)
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
If I were a god-fearing scientist, I would tell you that we live in an experiment designed to see how frequently RNA, DNA, and polypeptide-based life evolves.
Nah, the experiment is about creating silicon life. The hydrogens, carbons, nitrogens, oxygens and phosphors are merely catalysts.
If Pandora's box is destined to be opened, *I* want to be the one to open it.
You'll also note that if things didn't work out so perfectly, you wouldn't be here to invent god.
How did god evolve? Where did god come from? Why does god exist? Watches don't self-assemble or evolve from grandfather clocks; a watch implies a watchmaker. A being with the power to precisely calculate an asymmetrical space-time manifold where physical laws can come into being that allow something like stars and galaxies to even work must be much more complex than a watch. Who is god's watchmaker?
But as we know it was probably four elephants on the back of a turtle, and then it's a sequence of turtles, each more elaborate than the last to be the watchmaker for the next turtle.
Religion is fun and all until somebody gets hurt. I don't know where things are going with the religious right, but just keep in mind that if religion tells you that the only way to avoid hell and go to heaven is to kill somebody like me, that person might just be carrying concealed.
Probably best to stick to the real world. Fewer people get killed and fewer families get torn apart when there aren't sky wizards involved.
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