Elegran
Birds' wings have the same bone structure as our hands. How many of the same bones did pterodactyls and birds have in their wings? If so, the reason we have five fingers may go back a very long way.
Oh Elegran you have taken me back to being 16 and the first essay I had to write when I began A level Biology. I can’t remember the exact question but it was something along the lines ‘how is the pentadactyl limb evidence of evolution?’ . I’ve probably got that completely wrong but remember spending hours in the local library looking at different variations of the aforesaid pentadactyl limb and how it related back to a basic blueprint and a common ancestor for mammals, birds, reptiles and amphibians.
I particularly enjoyed looking at how horses evolved (horses being my passion) and discovering that they still have the remnants of those toes though they now walk on the very tip of only one. It’s fascinating. Perhaps someone with a better knowledge of the subject would be able to explain it better.