It’s clear we do need dragons, even if only for the sole reason that it’d be absolutely awesome!.. Reading this blog post made me think – how hard would it be to (bio)engineer a dragon? I’ve put some thought into it and a pinch of my biology and genetics knowledge, and figured that if I were to do it, I’d take into consideration the following steps.

First comes the chicken

Birds’ skeletons are already optimized for flying. Flying is a very energy expensive activity, and in higher animals energy is supplied by  a chemical reaction involving oxygen. The air-sacs in birds bones allow them to “store” the extra oxygen needed to fuel their flight.

Birds also have scales-covered legs. These scales are called scutes and they are evolutionary the same as the armor-like scales of crocodiles, turtles and armadillos. The fact that the birds already have the gene for suck scales, means that it’ll probably not be all to hard to make a bird-like creature covered with scales like.. Say a dragon impervious to some serious damage.

Alligator’s scutes

Chicken legs with similar formations

Fire breathing

Now this will be the tricky part. There are three parts to this question:

1. making a flammable substance
2. being able to store that substance and expel it at will
3. producing a spark that lights it up at expulsion

The first pint is the easiest – organisms that are able to produce flammable substance do exist. Methane is one of the most flammable gasses without being toxic. Transferring a gene from methane producing bacteria to a higher animal can be done, but comes with limitations. Methane production does not rely on a single gene but rather a whole metabolic pathway with multiple genes necessary to be able to produce it. Additionally, the gene might be sub-optimally expressed due to differences in the DNA-operating machinery and slight differences in the genetic code preferred by the bacteria vs the higher organism. If each cell in a giant organism produces methane, there’s no way it can be concentrated in a way that it could be expelled for fire-breeding. Instead, it would be much more practical to have the dragon be a symbiotic with methane producing bacteria, essentially like a cow.

Then comes the proper storing of methane. As already pointed out, birds have bodies filled with little air-sacs so one could set out storing the methane in these sacs. But that won’t do. In cows, methane is produced by bacteria in their intestinal tract, where oxygen is low or completely missing. Methane production requires the bacteria to be in oxygen-deprived environment. The air-sacs are used to fill with air (rich in oxygen) in order to supply it when needed to fly. And the air-rich environment is no good for the bacteria to produce methane. Instead, it could be an option to engineer the dragon to have a type of swim bladder like most fishes and have the bacteria colonizing it. Then, when methane is produced, it will be accumulated in that air-tight “swim bladder”. This is a good option also because it can be emptied at will – as fish are able to do it.  One hiccup is that, swim bladders are developed with the involvement of many genes, BUT scientists know already quite well the regulation of these genes, so engineering it in a dragon shouldn’t be impossible.

So the dragon has methane and can store and expel it when needed. Last step is to make sure, it can light it up. I guess it’s best to turn to fishes again. Some species have the ability to produce strong electric fields and discharges. These organs are made of evolved muscle or nerve cells (both of which the dragon will obviously have) and which can either be engineered in the dragon by directed evolution or even transplanted. By producing a very short but powerful electrical discharge from its electric organ, the dragon will be able to light up the methane it breaths out at the right time.

Make it BIG

Dragons should be big. But that is probably the easiest part – humans have been breeding animals to make them bigger (including chickens and other birds) in the scope of breeding programs. So in few rounds of breeding one can have a descent sized dragon.

And there you have it!

I made you a dragon! I wish that was the topic of my PhD thesis – I’m sure motivation would have been much higher! 😀 If one of you makes one, I’d love to see it – drop me a message!