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NASA-Funded Research Creates DNA-like Molecule to Aid Search for Alien Life
In a research breakthrough funded by NASA, scientists have synthesized a molecular system that, like DNA, can store and transmit information. This unprecedented feat suggests there could be an alternative to DNA-based life, as we know it on Earth – a genetic system for life that may be possible on other worlds.
This new molecular system, which is not a new life form, suggests scientists looking for life beyond Earth may need to rethink what they are looking for. The research appears in Thursday's edition of Science Magazine.
[...] The synthetic DNA includes the four nucleotides present in Earth life – adenine, cytosine, guanine, and thymine – but also four others that mimic the structures of the informational ingredients in regular DNA. The result is a double-helix structure that can store and transfer information.
[Steven] Benner's team, which collaborated with laboratories at the University of Texas in Austin, Indiana University Medical School in Indianapolis, and DNA Software in Ann Arbor, Michigan, dubbed their creation "hachimoji" DNA (from the Japanese "hachi," meaning "eight," and "moji," meaning "letter"). Hachimoji DNA meets all the structural requirements that allow our DNA to store, transmit and evolve information in living systems.
Also at NYT, Discover Magazine, and ScienceAlert.
Hachimoji DNA and RNA: A genetic system with eight building blocks (DOI: 10.1126/science.aat0971) (DX)
Related: Scientists Add Letters X and Y to DNA Alphabet
Scientists Engineer First Semisynthetic Organism With Three-base-pair DNA
How Scientists Are Altering DNA to Genetically Engineer New Forms of Life
Synthetic X and Y Bases Direct the Production of a Protein With "Unnatural" Amino Acids
(Score: 4, Interesting) by Thexalon on Saturday February 23 2019, @03:55PM (8 children)
My understanding for why the eggheads expect other life to be carbon-based is because other atoms don't allow for the same degree of complexity as carbon does. It's not merely an assumption that nitrogen or silicon or something else kinda similar couldn't do the same thing, it's that they've tried chemistry tests and found that they don't work.
As for DNA, it's not like I'd expect DNA to be universal, but I would expect that ET life contains some means of transmitting data from one generation to the next.
There are some adaptations of earth-based life that have evolved multiple times and are thus likely extremely useful. Other than that, I don't expect any resemblance at all between ET life and T life. That said, life as we know it is in many species much weirder than anything imagined by sci-fi: I mean, octopi, jellyfish, coral, sponges, lichens, giant networks of underground fungus, I know they have some things in common but they're really a lot stranger to us than Klingons.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 2) by EvilSS on Saturday February 23 2019, @05:01PM (3 children)
(Score: 3, Informative) by stormwyrm on Sunday February 24 2019, @02:44AM (2 children)
Boron is hardly what I'd call abundant in the cosmic scheme of things. It's actually a very rare element as it can't be made in bulk by any of the usual stellar and supernova processes, unlike carbon which is by contrast ridiculously common, since it is a direct product of stellar nuclear fusion. The universe started out with a lot of hydrogen and a little less helium, and very little of anything else. Given those two, stellar nuclear fusion can make hydrogen into helium, helium into carbon, carbon into nitrogen, etc. all the way up to iron, while stellar burning processes and supernovae can make even heavier elements. So just about every element in the periodic table can be made by those mechanisms, except for three: lithium, beryllium, and boron. The only known way these three elements can be made is from cosmic ray spallation [wikipedia.org] or possibly from the slightly less violent nuclear reactions in a stellar nova [soylentnews.org] (not a supernova, mind). I thus don't see it likely that boron plays much of a starring role in any form of alien life given its relative rarity. Though even so, remarkably, boron does seem to play a minor biological role [wikipedia.org] in normal earth life.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2) by Pino P on Sunday February 24 2019, @03:58PM
Boron... rarity... Is that what made Milla Jovovich's character Leeloo from The Fifth Element so special?
(Score: 3, Interesting) by EvilSS on Sunday February 24 2019, @05:16PM
(Score: 3, Informative) by crafoo on Saturday February 23 2019, @06:57PM
Right. Also, some other compounds can form and be varied and complex, similar to carbon, but the energy required to form/break them up is higher. Or the reactions happen at much slower rates. Or they only form well in the presence of fairly rare solutions. Carbon-based life wasn't just a random roll of the dice. Or, well, it was of course, but as far as the chemistry goes it's the most likely given the most common conditions and relative abundance of the elements.
(Score: 2) by HiThere on Saturday February 23 2019, @07:59PM
It depends on the temperature range you're working on. At any particular range there aren't many good information storing linear molecules that are both stable enough, and unstable enough. And there are so many variables that it's hard to envision an alternative working system. You can bet, though, that if they find life in Titan, it won't be based on water and DNA. And DNA is quite unlikely...but that doesn't tell us what the reasonable alternative would be. We can guess that it will be only partially soluble in a non-polar solvent...but that doesn't narrow the field very much. We can guess that we're talking about some chain molecule, but THAT doesn't narrow the field much either.
So just saying it's different isn't very helpful.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 2) by legont on Saturday February 23 2019, @09:01PM
I think it is more likely that there is only one kind of life around which migrated from one place to another. That's because the probability of self creating is just way too low for a single planet. Life migrates and does it often at different development levels.
Let's look at humans here. We have issues with joints and such and can't stand our sun without protection. Most likely we came from a smaller rock of a red star.
It's still possible that there are many variants. We may be a creation of some unethical hacker who shoot his half baked DNA design into space while escaping police.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 2) by edIII on Tuesday February 26 2019, @04:02AM
It's species of competing life adapting to their environments, which is why I don't suspect to see ET life resembling us much. It may resemble something on our planet, but not necessarily mammalian.
Life on our planet started in one environment, and then went though several stages. There's no guarantee that another world would've progressed the same way at all. We're changing the climate on the planet fantastically right now, which is only possible because trees evolved something nothing could eat at a time in our planet's history. IIRC, that's one of the reasons why we have these large reserves of oil, is because the planet kept accruing dead trees without the ability to convert them back into something useful for other life. Our exact progression depended on some variables that were provided by evolution itself, which is somewhat random. Like you said, some features have evolved multiple times within a species, and many times in several species or over long periods.
On top of that, you have the size of the planet, it's gravity, major minerals it's composed off, magnetic fields, tidal forces, etc. and you have even more variables that have to line up right.
I bet that if you reset Earth back to the beginning, it's not likely it would evolve the same way twice. I suspect that all of the randomness involved in our overall evolutionary process makes it unlikely for ET life to resemble us. It might be beating the odds to find something we can understand as other life, and certainly nearly impossible to be sexually compatible as popular sci-fi suggests.
Technically, lunchtime is at any moment. It's just a wave function.