This may be an odd question, but this is one thing I've always wondered. How does a dragonfly ancestor with early structures that will one day become wings gain any benefit from these useless limbs that don't work?
It seems in an intermediary context like this, that the adaptation would almost fall under a category more along the lines of something vestigial--something defunct.
I understand the creature adapts with no understanding or control of the process, and it takes extremely long periods of time to see any significant changes from one anatomy to another, but it would seem that statistically that would work against the animal, not for it. It's not like the dragonfly goes from the land and water to having fancy new fully operational wings.
The longer a species is stuck with an unhelpful adaptation, the longer they would be exposed and at a disadvantage. There is one way in which I could see this happening, and that is a prolonged series of random mutation in favor a winged route for the insect with no real input from their environment.
We all know that mutation and variation drift (all of which are relatively random) are part of the evolutionary process, but it is often described in more concrete terms, and the creatures in between an ancestor and a descendant have been discovered and described, but often not very well to the public.
The mutant albino bear ancestor being better suited for arctic stealth and eventually becoming the polar bear and diverging from the brown bear is an example given in the new Cosmos that actually could happen overnight. The bear is born with the full adaptation.
Even if the bear weren't instantly white, fur slowly becoming lighter leading to better hiding capability, or having a thicker coat to help it keep warm makes more sense than the precursor to an entire limb like wings or a tail though.
I suppose that it's possible to say the that random mutation is the primary method of evolution, and the apparent improbability of plants and animals surviving with incomplete, underdeveloped adaptations can be answered by realizing that the plants and animals alive today are the cousins of countless species that actually weren't helped by the wings, and some of that is random too.
And with that in mind, it's slightly more obvious, but I'm wondering if there's more to it or something I'm overlooking.
I've struggled to find any discussion about this topic in the literature, which I may have simply missed because it often goes over my head. I'm hoping my conclusion is helpful.
