Would an organism like a dragon be feasable?

[Dartz]

I got this idea when I was trying to brainstorm ideas for a science fiction. I want to write something where a scientist, using genetic engineering, creates a dragon. That got me to thinking, would such a creature be possible?

A dragon, as seen in many mythologies, is a large, flying reptile, capable of exhaling fire. I'm sure the flying reptile is feasible, since there were flying dinosaurs in the past, but I'm not familiar with any animal that can exhale flames. Would it be possible for an organism to safely shoot flames, and would there be a genetic code that would activate such abilities?

[Desacabose]

Yes

[vh]

Well there might be a genetic code for such a thing, but i doubt it is possible as of right now. We only understand around 3% of what DNA codes for (that is proteins), but the other 97% is pretty much gibberish. In fact, scientists call it 'junk dna'. We've been able to make bacteria produce insulin and sheep produce spider-silk though.

[smjjames]

There was a fake 'documentary' some time ago about how they'd work. The biology of the dragons of Dragonriders of Pern is a pretty good example of how they might evolve (minus the Nightcrawler-esque transdimensional teleportation).

[FiahOwl]

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[clockworks]

Why not? It's perfectly possible.
However on literally generating fire, I doubt it... but maybe like poison arrow frogs diet influencing poison on the skin, the dragons diet allows it to... make fire? Maybe it has special glands

[vh]

Well, generating fire could be achieved by hydrogen-generating bacteria in the dragon combined with some spark mechanism, maybe just using it's teeth.

[smjjames]

The teeth would have to be made of something that can spark, that is, metal. A more feasable option would be to use chemicals. The Bombardier beetle is a pretty good example.

Alternatively, they could spit acid or something.

Of course though, we are all assuming a carbon based biology and chemistry here, right? With other types of biologies and biochemistries, who knows what nature and evolution would create.

[vh]

Well, it could possibly have internal organs that cause sparks/fire. Something like the thing there you spin a piece of wood to start a fire. except more efficiently

[atomic7732]

What if it generated a chemical like boron whatever something that auto-ignited at a certain temperature.

[smjjames]

It would depend completely on the temperature that the organism lives in. With Earth range temperatures and terran-like biochemistry, I don't think that would happen.

Whatever the method of generating fire, the organism would have to do it in a way that it doesn't itself end up being on fire and dying.

[vh]

It would probably have to either ignite it outside of itself, or have some fire-resistant organ the fire comes out of.

[atomic7732]

It would depend completely on the temperature that the organism lives in. With Earth range temperatures and terran-like biochemistry, I don't think that would happen.

http://en.wikipedia.org/wiki/Autoignition_temperature

Triethylborane: −20 °C (−4 °F)
Silane: <21 °C (70 °F)
White phosphorus: 34 °C (93 °F)
Carbon disulfide: 90 °C (194 °F)

[vh]

I'd say white phos. and silane are too easily ignited here on earth. Probably Carbon disulfide would work best and still be reasonably acheivable.

eww fahrenheit

i'd say eww celsius too but i can't use kelvin fluently

[smjjames]

Triethylborane is toxic to the body and is corrosive, so, whatever uses it would have to evolve strong defenses against it. Also, any firebreathing would be restricted to very cold climates.

Carbon Disulfide could work, however, temperatures of 190+ aren't all that common on Earth (unless you're talking about specific environments like Black Smokers, hot springs, etc).

Regarding phosphorus, the element itself and related elements like sodium are very reactive, so something could possibly evolve to spit some sort of phosphorus goo. Which would be closer to napalm than fire breathing though.

For silanes, maybe silicon based organisms would be able to handle the toxicity better?

[vh]

That is the point smjjames, it wouldn't do for dragons to randomly light on fire. The Carbon Disuldife would have to be triggered by something to light and that would cause the hydrogen to light i guess. Possibly some organic chemical reaction

[atomic7732]

Considering as the list provided is likely incomplete, there might be something with an ignition around 50-60C that would work better?

Also keep in mind: "The autoignition temperature of a substance is the temperature at or above which a material will spontaneously ignite (catch fire) without an external spark or flame."

So the only thing needed would be something to reach the autoiginition temperature.

http://www.chemspider.com/ has a search for flash point but no search by autoiginition temps...

[karakris]

THe Dragons on Pern are supposed to Chew Rocks containing Phosgene.

This produces a self-igniting Gas, according to Anne McCaffrey - not sure how that would work, but maybe ??