Re 5
A creeping, mammalian thing, aggressively territorial,
The Cretaceous shrew’s our success story, sprung form an early placental.
Spreading his shrew-like fingers, arboreal standard issue,
A chip off the block in genes, blood and digestion too,
Man, a ganglion giant, gnaws species of a similar mould¹
To a common, well-chewed ancestor, being table-mannered in the fold
Where species are believed related by descent to others in Classes,
Each going their separate directions (Mammalia, Reptilia, Aves)
And in Orders in Classes (rodents, carnivores) going their ways,
Branching again and again to an agreement of generic traits.²
What else can we do but enumerate the ways in which species diverge,
For complex sprang from the simple - unless, of course, they converge?
Convinced that our animal ancestry was proved by anatomic evidence,
A history of aggressive behaviour loomed naturally clear fro Lorenz.
But we shift uneasily from one ancestral foot to the other,
As mammals and bird converge in warm blood to trace their mother; -
As the discoid placenta in woman was fashioned for a hedgehog frame; -
As the primate-bearing membrane thickens just the same
In the wombs of bats and rodents (not forgetting Tiggywinkles,
Spineless and Spiny); - as croc or avian cochlea unwrinkles
At the sound of its hominid descendant; - as well-defined nervous systems
In annelids and arthropods grope the soil of neurological consistence
With human kinship; - as in vestigial prehensile tail we recognize
Our chameleon and sea-horse lookalike, with the same great rolling eyes.
But the song of climbing feet and tail has widest resonance
Among would-be ancestors of man, all claiming family resemblance:
Primate (monkeys are favourite), Edentates (sloth and pangolin),
Rodents (the arboreal porcupine), Carnivores (the palm-martin),
Marsupials (the possum). How discrete Orders could evolve same structures³
(Like the gizzard in birds, earthworms, some fish) suggests an impetus
¹ ganglion giant suggests gangling, a mass of energy and nervous tissue; gnawing because we nibble away at taxonomic differences until we can assume a natural relationship between other animals and ourselves.
3 If we are related to birds because we are warm-blooded, we can also claim kinship with the crocodile because it possesses a cochlea, and with the earthworm because of its highly developed nervous system. To claim common ancestry in this way is plainly absurd. Creatures which belong to different Orders, but which have the same structures, point to the existence of parallel convergence, which conflicts with the Darwinian theory of species radiation from a common ancestor.
² Eg the roof rat is of the species and genus, Rattus rattus, of the,
Family, Muridae, of the Order, rodentia, of the Class Mammalia.