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Tuesday, November 24, 2015

Taxonomy Matters

"The royal, or giant, sable of Angola might someday even be stripped of its subspecies status, dismissed as a relic Hippotragus variant living out a twilight existence in the land between two rivers. But a certain mantle of meaning will always linger with the beast... if only because the Angolans see [it] with different eyes."

- John Frederick Walker, A Certain Curve of Horn

In my last semester of college, I actually got around to taking what was probably one of my most important classes - Conservation Biology.  The professor had a knack for being able to sum up complicated ideas in bumper-sticker catch phrases, as he demonstrated on the first day of class, when he scrawled "We're F---ED" on the chalk board as a summation of modern conservation theory.  A slightly more detailed, if less memorable, phrase came on a lecture on subspecies - "Taxonomy Matters."

It seems that before coming to campus, the prof had spent many a year in the field, a large amount of it devoted to studying an endangered subspecies of white-tailed deer.  After years of observing and monitoring and tracking and writing grants and proposals, he had a bomb-shell drop into his lap - his precious subspecies might not have been a subspecies at all.  They may have just been... white-tailed deer.

John Frederick Walker could probably share the feeling.  After years of idealizing the giant sable antelope of Angola, he was told by some South African geneticists that testings suggests that the giant sable is really no different from the other sable antelope of southern Africa.  Sure, it has special characteristics - really big horns, distinct facial markings - but those can be found in other sable populations, too.  Walker wasn't the only one to be horrified - if the giant sable lost its unique subspecies status, "Angola doesn't have a national animal anymore!" worries one conservationist.

Giant sable antelope bull (mounted) at the Field Museum of Natural History, Chicago

To be clear, there are still sable antelope running around the miombo groves of Angola, just as the white-tailed deer my professor studied wouldn't just up and vanish if their subspecies status was lost.  It would just mean that they are no longer considered a unique biological unique, distinct from all others.  And that can have major impacts of conservation.

This week, the world mourned the loss of one of the last four northern white rhinoceros in the world, euthanized due to age-related medical issues in San Diego.  With her passing, there are now three members left in the world.  But members of what?  Are they a subspecies, as most biologists maintain?  A separate species, completely distinct from the relatively-abundant southern white rhinos of southern Africa?  Or are they really no different at all?  If that's the case, then there's no major worry - they'd be interchangable with other white rhinos, and we could always move some up from South Africa, assuming things every stabilize in Central Africa, where the northern white is from.

Taxonomy (the science of the classification of living things) is a constant struggle between two camps - the splitters, who are breaking species into subspecies, or separate species, seemingly all the time, and the lumpers, who insist that differences in many cases are too minor to worry about.  Based on casual observations of zoology over the last two-decades of me paying attention, I'd say the splitters are winning. We had one species of clouded leopard when I was growing up, now we have two.  There were three species of crocodile in Africa, now we have seven or so (no one seems to know).  To be fair, the lumpers win occasionally, waving their wands and turning two species of tuatara into one.

A few years ago, this animal would have been considered a Nile crocodile (Crocodylus niloticus).  Now, it's listed as a separate species, the West African crocodile (Crocodylus suchus)

The animals themselves don't change, just how we look at them.  Unfortunately, that influences how we (or if we) decide to protect them.  Some people look at the rust-colored, leggy canids of the southeastern United States and see red wolves, a distinct species and one in dire need of protection.  Others see the hybrid of a gray wolf and a coyote, an animal of no biological importance, and one which we should ignore, focusing our efforts of other species.  Many scientists worked to save the giant sable because they saw it as something special and unique. If, biologically speaking, it wasn't, should those resources and energies have gone towards saving a "more deserving" animal?

Oh, me?  I tend to be a lumper, but only out of complete cowardice.  We have so many endangered species already in desperate need of conservation.  The last thing we need is more...

PS:  As of right now, both the giant sable antelope and the Columbian white-tailed deer retain their subspecies status, according to the IUCN

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