by Andrew Kerkhoff
"Now before the next class, be sure to watch King Kong," I say as the students squirrel away their notebooks. It is a favorite assignment, in part because a film about a giant, fictional ape who falls for a starlet, only to be exploited by a profiteering entertainment mogul, seems whimsically out of place in a biology course. Shouldn't we be studying actual organisms?
But the creatures of our imagination, from the Titans to the Terminator, have always had a way of telling us something deeper about ourselves, and Kong is no exception. The class in question, "Biological Scaling: Why Size Matters," is about how the conditions of life change for organisms simply by virtue of their size. In this context, we use King Kong to put our own, unique existence as modern, technologically advanced humans into a new perspective.
There are many ways to look at King Kong as a parable to inform modern life, but biologically, the key is energy. For animals like ourselves, energy means food. Enjoying a warm and comforting plate of enchiladas with my family feeds me on a number of different levels. Those beans, tortillas, and chilis also fuel my fundamental, and ultimately futile, struggle against decline and death, a struggle shared by all living things.
But for twenty-first-century inhabitants of the developed world, the food we eat is only the tip of the iceberg, energetically speaking. To function, we have to fuel not just our bodies, but our refrigerators and furnaces, our cars and airplanes, our tractors and factories, our MRIs and our iPods. And these technological energy requirements, which are as much a part of us as our arms and legs, dwarf our biological needs. Our metabolic rate is about the energetic equivalent of a 100-watt light bulb. However, in the United States, per capita power consumption averages 12,000 watts—more than a hundredfold higher than our food requirements.
So the question I ask the class, after they have watched the film, is this: How big would you be if all of that energy was just your metabolism? Based on the very regular mathematical relationship between metabolic rate and body size, the students can figure it out, and eventually the answer emerges: about 30,000 kilograms, or 66,000 pounds, or 33 tons. A few more calculations relating weight to height in primates gives us a height of 11 meters, or 36 feet. A 36-foot-tall ape.
Picture yourself, your children, your parents, your friends, everyone, as Kong. Imagine the lines at the grocery store or the scene on Middle Path. In class, we find that, given a larger door, Kong could just barely fit into Higley Auditorium. Picture him, reclining uncomfortably across the chairs. Imagine the smell, the sound of his slow exhalations. That is you. That is each and every one of us.
Interestingly, reproductive rates in the developed world, where population growth has slowed or stopped, are almost exactly what you would predict for such sizable simians—perhaps due to the energetic costs involved in rearing offspring who do not really wean until they graduate from college! On the other hand, our average population densities are enormously higher than you would expect for such a gigantic gorilla. In fact, the entire land area of the U.S., including Alaska, would only support around 9,000 Kongs at their "natural" population density, rather than the 309 million inhabitants estimated by the 2010 census.
And our "technological metabolism," the slow exhalations of 309 million Kongs, and about 6.5 billion slightly smaller but still gigantic apes elsewhere on Earth, has resulted in a massive release of carbon dioxide to the atmosphere, enough to alter our planet's climate. Our impact on the environment, like that of any other species, compounds our energy use and our population density, both of which appear to be growing unsustainably.
At the conclusion of the film, Kong, riddled with bullets, plunges tragically from the Empire State Building. Understanding our own "Kongness" highlights the energetic precariousness of the current human predicament. And hopefully, to paraphrase the ecologist H.T. Odum, we'll be able to find a more prosperous way down.