Credit: Mike Shapiro, University of Utah.
These two pigeon breeds -- the old Dutch capuchine, left, and komorner tumbler, right -- are not closely related, yet they both have feathery ornamentation on their heads known as a head crest. These pigeons illustrate the notion that birds of a feather don't always stick together, at least genetically, according to a new University of Utah study of the pigeon family tree.