Susanne, according to the well-organized discography at the Joan Baez Web Pages, "The Night They Drove Old Dixie Down" has appeared on a lot of her albums, mostly greatest-hits collections. The first album it appeared on was Blessed Are... (1971). The song is credited to J. R. Robertson, who of course is Robbie.

Barbara, I think the split between lumpers and splitters is universal in taxonomy.

Shambles, what Bill D. implied is right: I'm way out of my philosophical depth here. But... fuzzy edges make you doubt categories, but categories are still useful (essential?), and some ways of binning things may be more useful than others.

Katmuse mentioned what quacks like a duck, etc., and you were the one who brought up ruddy ducks (and then I dragged in the Aythyini).

Pete M., whoever made up that definition had never owned an entire male dog (or even a rabbit).