Also regularly see a lot of complete assumptions passed as fact. i.e. the King snake benefits from looking like the coral snake, it must have changed to look like the coral snake.
This is complete speculation and also strongly implies one existed before the other. We have no idea which of the two was extant in it's region first. Since the King snake eats other snakes including poisonous ones, it might be the coral snake that is benefiting from being confused with the King snake. That's a coin toss we have no idea which is even more likely.
I see a TON of this from within science, not limited to biology nature shows. FAR too many assumptions with little to no support or evidence passed off as fact. I get that it's leading or most credible hypothesis (based on what is known at the time) but then introduce or discuss it that way, not as accepted fact.
Again, we should be getting our own house in order on poor science presentation, especially the 'decently plausible hypothesis without hard evidence' automatically becomes hard assertion phenomenon.
Look at it this way:
"King" snakes currently and have always existed in a wide variety of colors and patterns.
All snakes are recognized as a predator species (but they are also prey to many other top predators; there are only a few snake species that are not considered prey--at least as adults...and I would say only a giant Anaconda would be avoided by all creatures).
So, there is a default natural avoidance provided to all snakes by some percentage of lower tier creatures. For predators, certain snakes are avoided on top of those that they would normally prey upon: coral snakes being one of those due to their high toxicity.
There are, by comparison,
only a few species of coral snakes.
In NA, all types of coral snakes have a nearly identical banding pattern, whether venomous or not. So, not only does the king snake take advantage of mimicry, but so too do other coral snakes.
It can be reasonably accepted that while King snakes continue to exist and thrive with all sorts of patterns in a diverse array of environments in the world, the "king coral" specifically evolved as an identification advantage afforded to the distinct patterning of coral snakes.
Perhaps there are studies out there, and further why this has been a long-accepted story, that shows where these species overlap you will find "coral-patterned" kings more prominently than you will other Kings, as local predators are well aware of the local venomous snakes.
Just because you see something is "complete assumption passed as fact," doesn't mean that it is. Perhaps you want an entertainment show like Nature on PBS to include citations after every single comment and wait for you to address every dozen or so articles before progressing to the next segment? Probably not; and like that fellow in the thread above, it would make for reading "the horrible wreck that is scientific literature."
Or perhaps, you could appreciate these shows for their intent: Educating the general public on accepted scientific fact in a lucid way that does not bore the laymen viewer with the hard language of basic science that is the foundation of the presented topic.
But I would bet that if it is already in your nature to distrust something that conflicts with a stone-encrusted belief system, exposure to the base facts wouldn't actually change your skepticism.