There is an increasing tend on the Stack to measure "possible, plausible, and probable" by Real Life
I've noted over the last six months that more and more people are judging questions by real life and not by the rules of the world of the OP. It's not overwhelming, but it is, IMO, a growing problem. However, the Stack has always had to push back on the science-lovers (and there's nothing wrong with science-lovers!) to remind them that worldbuilding is, somewhat by definition, fiction.
However, I've also noticed an increasing trend for people to ask questions like this:
- Is it possible to...
- Is it probable that...
This is a problem on this site, especially if you didn't go out of your way to specifically and in great detail identify the rules of your world. The knee-jerk reaction of the average reader (even I do it), is to compare the question to real life.
After all (and this is the important point), when you ask if something's possible, kinda by definition you're asking if it can really happen in real life.
The hardest for me are the questions about "possible evolution"
The class of questions I personally have the hardest time with are those where the OP is asking if it's possible for something to evolve. Think about it. We barely understand how humanity evolved and the science of genetic engineering is still very much in the science-fiction stage. Asking if it's possible for a fictional creature to evolve (or how it might do so) is, in my opinion, entirely opinion-based because there's no real examples we can draw from to establish a credible answer.
But, back to your question...
But, in general, you can help a lot by avoiding asking if something is possible. It's probably not what you're really after, anyway. It's more likely that you're wanting something like...
- Are there real-life examples of something similar to X that I can use to justify or rationalize X in my world?
- Is there science today that, if bent or looked at sideways, could rationalize X?
- Is there anything about X that stands out as impossible or unbelievable for my fictional world?
In other words, how you ask a question really is really important. You can't (and shouldn't) assume that we can or will understand your intent. It's not that we don't want to, it's just that we can't. I know all too well that writing the "perfect question" is very, very hard. But I do recommend putting the time into it — and above all, understanding what it really is you're looking for.
Because if you ask if it's possible for a 2-pound bird to fly with 30-pounds of tail feathers, the answer will likely be "obviously no, duh." Even if what you meant to ask was, "on my world gravity is a third of Earth's gravity and my 2-pound bird has densely-packed muscles that give it 5X the lift/push power of terrestrial birds, is my 2-pound bird with 30-pounds of tail feathers believable under those conditions?"
Edit: One last thing. Not about your question specifically, but speaking quite generally (especially in light of questions I've tried to help over the last week)... I've been wondering since I wrote this if people are coming to the site looking for some form of credibility or authority. In other words, what they're "really asking" is whether or not their concept is believable, but they're asking it in a way that invites us to Officially Authorize the Design for Worldbuilding Purposes. Almost as if they're expecting their friends to laugh at them for their design and so they want a real-world explanation or some authoritative action to prove that it isn't something anyone can laugh at.
The feeling that this is a growing aspect of the problem (from the querent's point of view) has been gnawing at me for the last week. Maybe I'm wrong and I'm just reading conclusions into a data set that's too small, but if I'm right, then future readers would benefit from the following observation:
No one on this site can authorize or validate anything. As our stated purpose indicates, we can only help you continue and complete the task of building a fictional world of your own design. Seeking anything else from us is, indeed, a mistake for many reasons. Perhaps chief among them is that your willingness to bring the offspring of your creativity to us is a great privilege that we should respect and enjoy, rather than judge. Our job is quite literally to help you achieve believability, not validity or real-world credibility.
No one has the ability or the authority to validate a work of fiction. If my observation is right in any way, then any action we take to validate an idea is nothing more than the other side of the same bullying coin the querent is seeking to avoid in the first place. In an ideal world, down voting only identifies displeasure with a question that has not been properly researched or is ill-thought-out and closure only happens because the question has violated one of the rules of the Help Center that serve to keep this site focused on Stack Exchange's overall goals and to encourage questions to be specifically useful to a broad number of people. Any other action on our part is, quite frankly, hubris. And we, the children of imagination that we are, should know better than to do aught but to embrace new creativity whenever it knocks on our door.
It is with great sadness that I acknowledge that betimes... that's not the case.