The earliest known use of the word "subspecies" in print was by Dampier, a
pirate by trade, though a naturalist at heart. He used it in reference to
some species of booby in the central eastern Pacific. A fair amount of
space has been devoted to some of those on this list --Nazca Booby, Masked
Booby , what else should l invoke? They were relegated to subspecies for
centuries, but are currently considered full species by the AOS and thus of
greater interest to birders in general.
As a young birder l was annoyed by the individual treatment of
subspecies in Gabrielson and Jewett's Birds of Oregon. English names in
boldface type headed a full account of "Red-backed Sandpiper" and
"Batchelder's Woodpecker". Any field guide today will portray that
red-backed sandpiper under the name "Dunlin", which apparently was
considered different enough from European birds to once rate its own name.
Batchelder's Woodpecker was in contrast to Gairdner's Woodpecker. l doubt
either is still recognized as even a subspecies, but the various
"subspecies" of sapsucker in that 1940 book are now in every field guide as
Yellow-bellied ,Red-naped, and Red-breasted. Oregon is one of a few places
where all can be seen, theoretically on the same day. They've been out in
the woods all the while, blithely unaware of the human constructs rising
and falling , each generation of academia leaving its own line of flotsam
on the shores of posterity.
DNA sequencing came along, and has been getting cheaper. This has led
to some major revisions--falcons are related to parrots, not hawks and
eagles. But it has frequently raised more questions, not settled old ones.
One would expect the potential to measure genetic distance between groups
definitively determining whether something is a subspecies or full species.
But there is no firm system, no fast calibration. Some sets of full species
show less genetic distance than some sets of subspecies. Sometimes birds
that clearly look different to the human eye display great ambiguity at the
molecular level. Then there are birds that appear identical to the human
eye, but when DNA is compared it's hard to call them anything but separate
species.
We are humans, constructing classifications for our convenience. The
birds we are attempting to label have their own agenda. I asked a
geneticist at OSU a few years ago about the pink-footed gulls. He had
sequenced pretty much everything from jellyfish to sealions during a 30
year career. He told me vocalizations would probably be more useful than
DNA to shed light on the Thayer's Gull. As Wayne mentioned, the Herring
Gull was the original basis for the Rasenkreits theory--horseshoe or circle
species if you would. It was the product of a couch in Vienna, Ernst Mayr's
, not Mr Freud's. Possibly the most successful fruit of armchair
ornithology to date, the Herring Gull as example failed upon the initial
attempts at DNA sequencing of pink-footed gulls. The concept does remain
alive among some practicing population biologists of renown and solid
funding. Save that foggy shore for another time.
I find most intriguing the dogma of separation as primary driver of
speciation. Coupled with the concept of competition, one gets undeniable
undertones of nationalism, laissez-faire capitalism, racial purity . As
real field work builds an ever bigger body of evidence, the role of
cooperation looms large. Coevolution is everywhere, between taxa, across
the boundaries of the various kingdoms of life. And a major driver of
speciation is hybridization. For generations biology students were taught
that wild hybrids were" less fit", essentially by default, while at the
same time being taught about "hybrid vigor" pursued by plant and animal
breeders.
