I like to point out the fact that vestigial organs are consistent with the phylogeny of the larger group. Whales belong to the mammal clade, and they have vestigial mammal limbs which the theory of evolution predicts were present in their ancestors. What we don’t see are vestigial organs that contradict the proposed evolutionary history of a species, such as vestigial feathers in a mammal species or vestigial nipples in a bird species. The evidence we derive from vestigial organs is not their relative lack of function but the consistency of these features with the phylogeny predicted by the theory of evolution.