Sunday, March 30, 2014

Venom, Vultures, and Rancid Ribs


Had you commuted to work with me each morning this past week, you would have shared the time-lapse experience of watching as vultures reduced a 60kg deer carcass from an anatomical intact road fatality on Sunday to a dancing, disarticulated fragment of ribs by Friday morning.  Courtesy of evolution of microorganisms inside the digestive tract of the American black vulture, Sunday’s bloody abattoir was no more delicacy than Friday’s final rancid ribs.  Given the progression of the week, I was invited to contemplate this theater of consumption and reflect on the meaning I’d find in its presentation. 

My son Zachary is studying herpetology at Christopher Newport University.  During an excursion through the woods behind our house last summer, we discussed the poorly understood evolution of snake digestion.  “Why is it,” I asked, “that certain snakes consume their food alive – albeit envenomed – while others constrict their prey and consume their food dead?”  Having been trained in physiology, I reasoned that there must be some enzymatic explanation for venomous snakes preferring their protein still fresh and oxygenated while constrictors are content to have hypoxic tissue in their diet.  I was disappointed to find that while the nearly 300 species of venomous snakes have been studied with respect to the composition of their neurotoxins and hemotoxins, far less research has differentiated the question I posited while tromping through the forest.  And as I read the few scholarly publications regarding the polyphyletic organisms within the phylogenic superfamily Colubroidea, I was intrigued to find that the same hyaluronidase that melts the wall of the oocyte allowing the sperm fertilize the egg in mammalian reproduction is uniformly found in both neuro and hemotoxic venom.  It turns out that the genesis of mammalian life and agency of reptilian predation share a common goal – dissolving walls that divide and disintegrating barriers to essential, life-giving proteins.

So it is with quite some sobriety that I found myself contemplating the nature of consumption in the guts of snakes and vultures and reflecting on the persistence of both of these animals in cultural iconography over the millennia.  Did our ancestors know more about what was knowable about life, death and their interplay than we do today?  Is that why they pointed us to snakes and vultures in art, religion, poetry, and myth?  Maybe.  Or maybe I’m just juxtaposing unrelated observations to make a point. 

Vultures rely on bacteria within their digestive tract to counteract bacterially produced toxins from Bacillus anthracis and Clostridium botulinum – anthrax and botulism, respectively.  And while we focus on the “how do they eat rancid meat and not get sick like us?” question, we fail to observe that, like snakes, their digestion has been adapted over the arc of evolution to consume with specificity that which is in abundance within their habitat.  The bacterial load with the vulture’s gut and the toxicity of the venom produced say by the Crotalus scutulatus (the venomous pit viper found in the desert Southwestern US) far exceed the amount required for the beneficial toxicity.  In other words, the animal is far more effective in the production of protective proteins to achieve the venomous objective than would be required.  And the reason for this, to say the least, is not understood at present.

But, for a moment, let’s go back to my favorite sentence thus far – the one that ends the second paragraph.  The goal of all of these evolutionary adaptations is to both serve a metabolic mandate for the animal and serve an ecosystem balancing role in the elimination of carrion and prey respectively.  Informative within this reflection is that the consumer has engaged in adaptation to achieve the singular benefit desirable for its engagement within the ecosystem rather than seeking to manipulate the ecosystem to favor its objectives.  And this, ironically, applies both to snake venom, vulture guts, and mammalian reproduction.  Permeability for provisioning life – the enzymatic mandate of hyaluronidases – is not general in its application but rather it is highly focal and specific.  If one were to simply spray these enzymes across the ecosystem, we’d be reduced, quite literally, into a gooey ooze. 

It appears, upon closer inspection, that we could learn a lot from a serpent.  It may be no small coincidence that we’ve developed elaborate social, religious and cultural metaphors to steer clear of what they can teach us.  “Unclean birds” and “serpents” – examples of autogenic consumer adaptation – are relegated to the ick-factor while gluttonous grazing beasts are revered.  Now, don’t get me wrong.  I think there are a lot of cows and camels that could teach us a lot about life but I’m particularly fascinated by the consumer evolutionary intelligence of vultures and snakes. 

What would our consumer industrial complex look like if we took on some responsibility to modify ourselves to be more suitable consumers in our ecosystem?  Much of what we seek to describe in economic terms are inefficiencies we project upon our ecosystem so that it conforms to our desires.  Much of our associated conflicts arise from the dissonance we impose on a world we want to manifest in our illusory image.  But, in this impulse lies the seed of persistent conflict.  We – now I’m speaking about the whole of humanity – are no more identical in our aspirational consumption than are the 300 different species of venomous snakes.  Some of us like the crunchiness of a paralyzed mouse while others of us prefer the sedate, lifeless piglet.  And the reasons why our preferences differ is, in part, because of the enzymes in our digestion which make one form palatable over another.  With over 2,700 varieties of snakes – only 300 of which adapted to envenomate prey – and with hundreds of Falconiformes – only a subset which feed on carrion – do we really think that we can find a single enzyme of consumption that is common to all of us?  Not a prayer!

So where does this leave us?  Great question.  What I know is that this parable of consumption was my obsession this week.  I do know that it’s serving as another lens through which I’m observing economic systems.  And I know that, at present, this is merely the carcass of the idea which, when fully digested, will look quite a bit different.  Chew wisely!


1 comment:

  1. The image that came to mind for me while I was reading this post David is the 'always already' movement of both the involution/evolution dance attempting to find equilibrium as form moving towards 'Symbiosis' as per Unified Theory. All is dynamically forming, in formation toward this ultimate artifact. See table here: http://sharedimagesopen.files.wordpress.com/2014/03/unified-science.png?w=700&h=290

    Maybe the 'ecology of the mind' is moved similarly?

    ReplyDelete

Thank you for your comment. I look forward to considering this in the expanding dialogue. Dave