Could Real Dragons Ever Evolve?
By: A. S. Deller
Tags: Science, Biology, Fantasy, Evolution, Monsters

Dragons are the single most ubiquitous and recognizable mythological creature ever dreamed up by the human consciousness. They crop up in hundreds of cultures around the world, from China and Hawaii to New Zealand and Iceland.

These mighty, fantastical beasts hold a special place in our tales, from Smaug to Toothless, King Ghidorah to Mushu, Falkor to Fafnir, dragons entrance us with their power, graceful shapes and movement, and sometimes even wisdom.

David E. Jones, an anthropologist, believes he has come up with an explanation for this in his book An Instinct for Dragons. Jones studied vervet monkey troops of the African savannah and realized that their primary predators are raptors (birds of prey), snakes and big cats. These would have been roughly the same for humanity’s earliest ancestors such as the australopithecines. He posits that this gave rise to a deep-seated, inherited fear of such animals which has stuck with us throughout our evolution, and made its way into our nightmares and, by extension, tales of monsters.

Beowulf, St. George and the dragon, the story of the dragon’s pearl — Stories of these chimeric beasts go back thousands of years, to the very dawn of written language, and likely back to the beginnings of spoken language as well. The ancient Chinese philosopher Wang Fu even wrote of dragons as having the claws of eagles, feet of tigers and necks of snakes.

Dragons, as we imagine them, are generally reptilian in most of their features, although many possess hair, horns and even feathers. Another thing they usually have in common is large size. These factors are also seen in the “thunder lizards” that we know existed in our real world’s distant past: the dinosaurs.

We know of hundreds of dinosaur species that evolved for flight like the microraptor, as well as archosaurs such as the pterosaurs. The largest of these seems to have been Quetzalcoatlus northropi with a wingspan that reached 36 feet, roughly matching the size of many dragons of myth.

A common misconception is that birds evolved from these flying dinosaurs. However, paleontologists have known for decades now that our modern birds actually descend from terrestrial dinosaurs related to small theropods like the velociraptor. These creatures took to the trees to hunt and scavenge. Those with mutations that helped them survive falls — such as flaps of skin growing between fingers and arms, and proto-feather scales — lived longer and had more offspring, passing on these mutations until they became more prominent. Eventually, the forearms became wings, and the feathers grew larger, and the aves class was born.

In our fictions, there are numerous basic body plans for dragons. The three primary ones are: four legs with two separate wings that sprout from above the foreleg shoulders; an avian body plan with two rear legs and the front limbs as wings; and the elongated serpentine body with (or without) two or four legs.

No larger, more complex land animals have ever evolved on Earth that exhibited more than four limbs. Indeed, all mammals, reptiles, amphibians and birds either have, or are directly descended from animals that had, four limbs. Fish are the one complex class of animal today that departs from this body plan, though all of the other classes (tetrapods) evolved from from them.

The most realistic possibility, therefore, would likely be a giant reptile evolving toward the body plan of a bird, as seen in Game of Thrones. Size becomes the most constraining factor, however. Thickly built, muscular dragons of substantial dimensions would not be able to generate enough lift with wings that were remotely proportional to their bodies. Our modern flying birds, and the flying reptiles of the past, only managed flight due to hollow bones and either very large wings and/or robust feathers.

But what about some other very common characteristics of dragons: intelligence, extremely long lives, and the ability to “breathe fire”?

In some modern large reptiles and birds we see intelligence comparable to that of some primates. Crocodiles and monitor lizards can be canny hunters, while crows consistently rank among some of the most intelligent problem-solving animals. We also find a number of reptiles that can live for over a century, such as tuatara lizards and giant tortoises.

Lastly, we have the oft-described fire breath. A number of creatures eject poisons, such as spitting cobras. The archerfish shoots a tiny blast of water to knock insect prey down into the water. But shooting flame is another thing altogether. However, this may not be impossible for a giant reptile. An insect called the bombardier beetle combines hydrogen peroxide and hydroquinone and fires this out from its abdomen in a stream of chemicals to the boiling point (100 degrees C). It may not be so far-fetched to imagine a similar mechanism evolving in a giant winged reptile: Glands could exist in its gullet that secrete multiple chemicals that, when joined, produce a superheated reaction which is then expelled through the creature’s open mouth. Research biologist Brian J. Ford posits that such a chemical could easily be produced biologically. Animals in a state of ketosis naturally create acetone, which is highly flammable. Perhaps our dragon controls this production and emits a stream of acetone, which in turn passes by a specialized structure of teeth or scales that strike together to create a spark and ignite the acetone — thus generating a gout of flame that sears the beast’s prey.

While the existence of any mythological beings should always be dealt with skeptically, it is not completely beyond the power of evolution to result in something that physically resembles and behaves in the way of legendary dragons. Such creatures could have existed in the distant past, some hundreds of millions of years ago, or might still evolve millions of years from now. If (or when) another mass extinction event takes place, and humans are knocked from our place at the top of the mountain, an opening might remain in which some reptilian or avian survivors advance over the ensuing millennia. Growing in size and strength, ultimately these creatures could reach the status of apex predator, ruling sky and earth.

And, considering the growing capabilities of gene editing, we could one day even create dragons ourselves…

Thank you for reading and sharing!