There's an Albanian legend that says when a snake lives a long enough life without ever being seen by a human it turns into a dragon.
Some more recent experiments (http://www.americanscientist.org/issues/pub/the-reality-of-watching) seem to have removed the anthropomorphism from the quantum observation effect but for the moment lets keep it in there...
When the world was young and men were few there was a higher chance that a creature could spend its entire life without ever encountering humanity. What if this dearth of humans beyond the frontiers mathematically facilitated the existence of dragons, unicorns, ettins, elves, etc. Imagine a whole world of fantastic creatures that spring to life out of time, isolation, and the uncertainty principle. The more unpopulated the world is, the more weird it is. More than by our actions, humanity "subdues" the world by our very presence and observation.
That article above talks about an experiment where they distinguished between what was actually known and measured and what was only measurABLE and said that the was no difference. That one in particular suggested that it wasn't an observer (certainly not a human one) that was critical, but a system that contained genuine uncertainty. I'm not sure how that dovetails with the Weismann experiment that follows since the effect happens only when the sensors are active but whatever. Anyway, it makes me wonder about the difference between what's knowable and what's conceivable. In this world where fantastic creatures pop up literally out of human ignorance it begs a question of where those creatures get their seed. Does a snake turn into a dragon because there exists a seed of a dragon in the minds of those closest by? Local myths and legends create the seeds of these creatures and thereby account for a kind of local variability. Why doesn't this snake change into a football or a sack lunch? There's a certain kind of logic that runs from snake to dragon - maybe it's a little like an evolutionary tech tree. Baked into the reptilian DNA is this sting of potential mutations. From the more mundane to the more fantastic the chances of this mutation are smaller and smaller and the presence of humanity acts as a dampener on these numbers.
Something in here could make a set-up for a cool Sci-Fantasy story...does that genre exist? I remember a concept from Shadowrun where the elves and dwarves and Orc were always with us but as the force of magic retreated from the world, those races sort of integrated into humanity. But when magic returned they started to differentiate again. I found that idea just wonderful and fun and full of potential.
Anyway, that was the idea, who knows if I'll ever get the chance to play with it.