"Honestly, I can't believe this nonsense is still being bantered about."
You need to take a science course.
By who, a cloaked figure in a dark alley saying: "pssst, I got ur science right here...."
I'm not going to bore you with the details because you probably won't believe me anyway, but suffice it to say that medical science does not consider these things vestigial, or gills, or tails...
Recapitulation theory (ontogeny recapitulates phylogeny) is nonsense, and has been shown to be nonsense.