Toward the end of chapter 2, Osha Davidson describes the long-term relationships we discover between living organisms, symbiosis, as a “kind of marriage.” As he further states, “Not all marriages are made in heaven, and neither are all symbiotic relationships” (17). Marriage is an apt metaphor for the “union” of two different creatures that, in some scenarios, cannot survive without the other. Parasitism is, indeed, a marriage that is NOT made in heaven – but rather, more like the marriage between a blond gold-digger
and rich oil tycoon. The gold-digger receives the benefit, while the oil tycoon gets sucked dry. Similarly, in the animal kingdom, parasitism is a marriage wrought with disparity. Consider Ascaris lumbricoides
a parasitic roundworm that infects humans, typically in subtropical climates. Ascaris
uses its human host as a warm protective home, a feeding trough, and a center for reproduction. The human host receives nothing beneficial from this relationship, but rather, comes down with minor infections, perhaps a nasty cough (the infected human coughs up immature worm larvae), and in serious cases, may suffer intestinal blockage.
But moving on to more blissful marriages, mutualism is a symbiotic relationship where both parties receive a benefit. Mutualism is a happier union than parasitism, or even commensalism
for that matter. Osha goes into great depth in this chapter, detailing the intricate balance between coral and their endosymbionts, the zooxanthellae (or zoox). As Osha states on page 17, “ […] in the case of the coral and the zoox, the symbionts are virtually inseparable, coexisting in a single unit, the coral polyp, from generation to generation, evolving together over thousands of years.” Just as in a good marriage, the two organisms take care of each other, providing basic needs so the other can survive.
But what happens when a “good marriage” goes bad? Take coral bleaching
for example – many different factors can cause coral to expel their zoox, ranging from a slight increase in water temperature to increased sedimentation. These two organisms truly are inseparable; in fact, when coral expel their zooxanthellae over prolonged periods of time, many of them do not regain their algae, and because of this, may die.
Reading this chapter made me think of many questions. First, if corals and zoox had thousands of years more to co-evolve, is it possible they would become one organism? This question isn’t really that far-fetched, especially when you consider that some scientists believe that mitochondria, the organelles within our cells that make ATP
, were once symbiotic bacteria. The only other thing I wonder here is if corals will actually have thousands of years more to evolve. As Osha put in his preface, “Whether this work [his novel] turns out to be an ode or an elegy is still very much an open question, and the answer lies – where else – in our hands” (xii).
Secondly, at what point do taxonomists declare that the corals and zoox are, indeed, one organism? I wonder what characteristics have to be present in order for this to occur? When does this "enchanted braid" of animal, mineral, and vegetable become one being?