As I understand it, those sort of relationships rely on the reasonableness of human-defined taxonomy.
For instance, if we referred to eels as "snakes" then they would have less in common with other snakes than they would with fish (I believe they are closely related to fish anyway, I might be wrong there).
Also, there are also some relationships that many might find surprising. For instance, most people know that birds and reptiles are fairly closely related, but the fact that crocodilians (alligators, crocodiles, etc) specifically are the closest living relatives to birds might be surprising. Personally I would have guessed some sort of more nimble reptile, lizards perhaps.
For instance, if we referred to eels as "snakes" then they would have less in common with other snakes than they would with fish (I believe they are closely related to fish anyway, I might be wrong there).
Also, there are also some relationships that many might find surprising. For instance, most people know that birds and reptiles are fairly closely related, but the fact that crocodilians (alligators, crocodiles, etc) specifically are the closest living relatives to birds might be surprising. Personally I would have guessed some sort of more nimble reptile, lizards perhaps.