My 3 cents. Nature does not believe in categories. Taxa are created by
humans. Since everything is related to everything else drawing the lines is
going to be controversial. You would think the easiest place to make
distinctions would be at the kingdom level but the more we find out the
harder it is to decide where one kingdom ends and another begins. I bet
there are more problems today than there was when we had the old 2 kingdom
system. Now we simply throw everything that doesn't fit in the four
or five existing kingdoms into protista. It seems the more we know the more
we don't know
D. Haas
