Since ungainly and slow flying seems counterintuitive to survival, it’s a good question to wonder if it has a purpose. Questions like this drive scientific inquiry and inform phylogeny. Framing our pursuit of understanding as “reductionism” is odd to me in a citizen-science platform. Answers may be complex, most will be incomplete, and many are unknown, but that doesn’t mean folks should be happy with simple description without the desire for deeper understanding. We should be wary of Just So Stories in the absence of evidence, but honest speculation isn’t reductionism either.
I went looking for articles that address the long legs and mode of flight. This one notes an observation that some taxa have many tracheae in their legs, which make the structures light and play a role in respiration. https://uwm.edu/field-station/phantom-crane-fly/
I have no disagreement with what you have said. I was merely advancing another philosophical stance.
Again, I do not disagree. It’s what keeps our understanding of things going. Again, I’m merely advancing another perspective on things. Not a popular one, I agree, but valid all the same. It is difficult to do a forensic analysis on many present things, considering our lack of understanding of how they actually came to be. I do flip back and forth between the two perspectives, but am comfortable with not knowing.
Speculation here. Videos of crane flies laying eggs are quite interesting. They disperse their eggs while walking, and their legs make that mode of egg-laying quite efficient. So perhaps that efficiency is one functional advantage of the long legs, at least in species with this egg depositing strategy. https://www.youtube.com/watch?v=1WEMwD-7y-Q
Maybe it’s the opposite, they don’t need to be good fliers for survival? All Nematocera imo are not perfect fliers, opposed to Brachycera who for many purposes “try” to perfect their flight abilities. It would be interesting to know what lifestile that ancient taxon had, and as it’s Limoniidae already in Jura, when this bodytype first appeared and what kind of world it was at the time?
I have seen crane flies perched, doing a constant “shimmy,” that is, their body gyrates as their feet remain in one spot. I could see this being a predator-avoidance behavior, creating visual confusion and a blurred outline. A short-legged fly could not do that.
One day I happened to be caught out in a rainstorm at the local community garden, and noticed that while just about every other insect had taken cover, the craneflies were out in great numbers. It made me wonder if their long legs are useful for navigating puddles, or stabilizing flight in the rain, or…???
To me, a crane fly looks like it’s possibly built for wind dispersal. Long narrow abdomen, long legs, fairly long and narrow wings, and overall light and delicate body plan. I think they’re considered weak flyers. The legs could assist in getting lift or stabilizing flight (or gliding). I know nothing about their life history, so just a wild hypothesis.