Tag Archives: DNA

Biotech to the stars

dendritesCentauri Dreams discusses a DNA-based self-replicating interstellar probe:

Think of a probe that gets around the payload mass problem by using molecular processes to create cameras and imaging systems not by mechanical nanotech but by inherently biological methods.

A Von Neumann self-replicating probe comes to mind, but we may not have to go to that level in our earliest iterations. The biggest challenge to our interstellar ambitions is propulsion, with the need to push a payload sufficient to conduct a science mission to speeds up to an appreciable percentage of lightspeed. The more we reduce payload size, the more feasible some missions become

This is similar to Robert L. Forward‘s starwisp concept (popularised by Charlie Stross in Accelerando).

I suspect that if and when we do get round to interstellar exploration it will involve sending small-mass packages that are capable of bootstrapping themselves to a broadcast/exploration mode using local materials on arrival in the target system.

It remains to be seen what kind of space-based molecular replicating systems become viable. Will we be able to create space-hardened bioware, or good ol’ fashioned machine phase fullerene nanotech?

[image from neurollero on flickr]

Culture is carried by DNA?

pair of Australian zebra finchesIt sometimes feels like you can’t go two weeks without some new aspect of human life or behaviour being declared as being related to our DNA. The latest attempted conquest of genetic determinism? Why, our very culture itself!

You see, male zebra finches usually learn their courtship song patterns from their fathers, but it turns out they can generate the same songs spontaneously after a few generations without influence:

“It’s the classic ‘chicken and the egg’ puzzle,” Mitra said. “Learning may explain how the son copies its father’s song, but it doesn’t explain the origin of the father’s song.”

Mitra’s team wanted to find out what would happen if an isolated bird raised his own colony. As expected, birds raised in soundproof boxes grew up to sing cacophonous songs.

But then scientists let the isolated birds give voice lessons to a new round of hatchlings. They found that the young males imitated the songs — but they tweaked them slightly, bringing the structure closer to that of songs sung in the wild. When these birds grew up and became tutors, their pupils’ song continue to conform, with tweaks.

After three to four generations, the teachers were producing strapping young finches that belted out normal-sounding songs.

Uhm. Well, if you’re thinking that seems a little tenuous, you’re not alone:

Mitra admits that the analogies between bird culture and human culture are tenuous. “But there are resemblances. Culture is just learned behaviors. The motivating scenario is, if you isolate human babies from culture, put them on an island and come back after a few generations, what would their culture be like? What sort of language would they have? What sort of politics would evolve?”

That experiment probably won’t take place in the near future. In the meantime, Fitch says we can learn valuable lessons about human culture from songbirds, both at theoretical and mechanistic levels.

“Social learning is shared between the two, and songbirds are a well-understood and experimentally tractable system,” he said. “These biologically-grounded studies will lead us beyond the tired ‘nature versus nurture’ or ‘biology versus culture’ dichotomies which dominate the social sciences today.”

With the caveat that I’m not a geneticist or behavioural scientist, I don’t really see how birdsong and human politics are supposed to be different expressions of the same thing; the former is a biological imperative, while the latter is an emergent phenomenon. As Brian Eno once said, “culture is everything we don’t have to do”; a zebra finch that doesn’t sing sweetly won’t pass on its DNA, making its songcraft a matter of reproductive necessity, but I don’t think you can declare the same thing about, say, a great human painter or poet or politician.

That said, I’m all for getting beyond the nature/nurture dichotomy – knowing how culture emerges from biology is one of the most tempting grails of knowledge I can imagine. But in the same way that everything from alcoholism to sexuality seems to be blithely written off as being primarily a function of our genetic code, declaring such a nebulous and complex phenomenon as human culture to be passed along by DNA on the basis of some songbird studies seems… well, it seems pretty daft, really.

If there’s someone in the audience who can set me straight on this subject, I’d be very glad for them to speak up and tell me where my reasoning is wrong, but this story seems to me like just another instalment in our ongoing fetish with genetics as the key to all unsolved mysteries. [image by Lip Kee]

Gattaca becomes reality – all babies to be DNA sequenced at birth by 2020?

digital rendering of DNAA genetics outfit named Illumina is preparing to launch an affordable genetic mapping service in the next couple of years. Its first few customers can expect to pay between US$10,000 and US$20,000 for a complete mapping of every gene in their DNA, but their chief executive has told The Times that by 2020 the equipment should be so affordable that all newborns will have their genomes sequenced at birth:

“The limitations are sociological; when and where people think it can be applied, the concerns people have about misinformation and the background ethics questions.

“I think those are actually going to be the limits that push it out to a ten-year timeframe,” he added.

Of course, he’s bound to be positive about the prospects; CEO of the company isn’t exactly a disinterested position. But I think that’s a pretty plausible timeframe, if only so far as the capability is concerned.

And there will be resistance to the idea, even if the Gattaca comparison is rather overstated. Given the UK government’s current obsession with storing the minutia of its citizen’s lives, I’d be worried about letting them have my entire genetic sequence – though not because of what they would use it for so much as that I couldn’t trust them not to leave it in a briefcase on a rush-hour train

Even that makes light of a potentially sticky ethical quagmire, though; we won’t get to see everything that’s hidden in Pandora’s box until we actually open the lid. Let’s just hope we’ve gotten over our little global obsession with copyright and intellectual property by the time the street-corner sequencer shacks open for business, eh? [story via FuturePundit; image by ynse]

Productive Nanosystems – The Movie

Most of us are aware that DNA and RNA are the molecular machinery that synthesise proteins and allow the complex reactions of life to take place, but actually visualising the processes is a considerable mental leap.

Most such visualisations rely on visual simplifications that actually present a false impression of the processes involved, but via Eric Drexler we discover the following examples by Drew Berry, which are apparently much truer to the actual processes that occur. Take the seven or so minutes needed to watch this, and you’ll be set up for your daily dose of scientific sensawunda for the rest of the week – biochemistry is incredibly awesome:

Aside from the sheer wow-factor of seeing molecules acting like high-precision machines deep at the cores of our cells, it’s worth bearing in mind that there’s no magic involved, and that we’re constantly getting better at understanding how these processes work.

Which, I expect, is why Drexler is so fascinated by them: once we know how the body’s nanomachines work, we’ll be properly equipped to start building new ones.

Are you ready for personalized genomics?

genome Personalized genomics–a rundown on your inherited risk for certain conditions–is becoming a reality.

A couple of hundred dollars, a few drops of saliva and a stamped envelope is all it takes to get a rundown on your inherited risk of around a hundred more-or-less common conditions, everything from bladder cancer and baldness to male infertility and memory loss. You can place your order by Internet with companies like 23andMe (“genetics just got personal”) and deCODEme (“deCODE your health”).

The cost of sequencing an entire individual genome is about $100,000 right now, and Pacific Biosciences in Menlo Park, California (“a revolution in DNA sequencing is coming”), says it will be able, by 2013, to map all three billion base-pairs of a person’s DNA in a quarter of an hour for a few hundred dollars.

Critics are not enthralled. Many diseases are the result of a complex interplay of many different genes that we’re just beginning to understand. And there is fear that people with dicey genomes could be discriminated against by employers, insurers and banks. (President George W. Bush signed the Genetic Information Nondiscrimination Act in the U.S. last year for that very reason.)

But here’s the real question: do you really want to know everything your genome could tell you? Is there any benefit in knowing you’re, say, 20 percent more likely to develop a fatal or debilitating disease? Might the worry about that possibility be almost as damaging to your quality of life as the disease itself?

What do you think?

As fast as the technology as advancing, you don’t have long to make up your mind.

(Via PhysOrg.)

(Image: U.S. Dept. of Energy Office of Science.)