Some traits are similar between different species, and taxonomists describe some of those similarities as “plesiomorphic.” by this term, taxonomists mean _ the trait has been changed in one or the other of the species since the time that they last shared an ancestor in common the trait has remained the same in one or the other of the species since the time that they last shared an ancestor in common the trait is not dominant, and will eventually disappear from the population the trait is interfering with reproductive success, and will disappear from the population very soon