We have a tail-bone, but we do not have a tail. It is vestigial, originally serving a purpose, and now is an unfavourable allele. And that is visual proof of evolution; the systematic change in the frequency of genes in a population so that favourable characteristics are passed down and become more common. There are so many examples of this: Moths during industrialisation, antibiotic-resistant pathogens, pesticide-resistant insects, camouflage among many others. As said before, it is all over the place and it is moronic to deny it.