Vestigial

Vestigial organs, what a waste!
They are problem-laced.
They were useful long ago,
But now their use is low.
Wisdom teeth are taken out.
Tiny mouths shouldn't pout.
Yes, there is a smaller smile,
But we'll heal after a short while.
As with the teeth, the appendix helped with salad greens;
But appendices burst by any means.
The gall bladder helped with slowly digesting fats.
Our ancestors went a day before finding meals with their bats.
Some people are born with tails,
Which make it awkward to sit on pails.
We go through natural selection.
As we evolve, parts go through un-selection.
Someday we won't have to worry about wisdom teeth, gall bladders, appendices and tails.
Evolution seemingly never fails.