I got to talking with my daughter today about the scientific classification and realized just how little I remember but she on the other hand remembers quite a lot.

There must be a good reason we need to have a
...Domain broken down into
...Kingdoms broken down into
...Phylum broken down into
...Class broken down into
...Order broken down into
...Sub-Order broken down into
...Family broken down into
...Genus broken down into
...Species.

I suspect the reason is because there are just so many living organisms with their own little quirks to necessitate such classification.