The thing about Phylums and Classes and Orders and all:
They don’t really mean very much, from a-one to another –
They don’t show a definite border or wall,
Except that each member within is a brother.
But how shall we simply compare, say, a Fam’ly of fishes
With Fam’lies of insects or fungi, or some other race –
For nature won’t readily yield to our wishes
For systems and schemes with all life in its place.
What’s needed are rankings that indicate something specific,
Like maybe the age when such clades were diverging anew –
There must be a way to be more scientific
That merely to shrug and decide “this’ll do”.
Then maybe some Kingdoms or Phylums will prove to be hoarders,
While others lack class in their Classes, now under-supplied.
So finally, let’s bring an order to Orders,
And give ev’ry Genus some Family pride.
It always struck me that the Linnaean ranks would be more useful if either all of their inhabitants shared a minimum percentage of genes, or alternatively that they were diverging at roughly the same time as all the others of that rank.