Biomimicry is a complicated attempt to arrive at simple, natural solutions that often result from the Ideal Free Distribution.
I am pre-publishing this sequence of essays here and in social media to elicit comments and other feedback. They will form the framework for my next book, Darwin, Dada, Dalí, Duke, & Devadevàya.
The Ideal Free Distribution
As we noted in the previous post, ecology seeks to predict animal behavior. Economics seeks to predict human behavior.
The two can inform one another, and they often do. For instance, consider one of the simplest of these ecology-economy convergences, the ‘Ideal Free Distribution.’ Economics has sophisticated ways of looking at this, but the ecological explanation is quite simple. Take 10 cats, divide their food up 7:3 between two large bowls a few meters apart. Very quickly, 7 of the cats will end up at the first dish, and 3 at the other.
The interesting thing is that often, non-thinking organisms presented with choices will quickly arrive at the same solution. They just move around a bit until they maximize their intake, and distribute themselves in ratios that match the resources.
I did an experiment with bumblebees where I was simply trying to demonstrate the bees’ preference for floral nutrition over appearances. When I looked at my data, however, I was surprised to find they had distributed themselves almost exactly in an Ideal Free Distribution.
This theory is not perfect, and biologists struggle with some experiments where animal behavior seems to diverge from the ideal. Nevertheless, there is a lot of evidence that animals distribute themselves according to the availability of resources. Actually, all living things do, it’s just that animals react the fastest, and so they are the easiest to test and measure.
Grocery Store Choices
Humans also conform to the Ideal Free Distribution. In the grocery store, we glance around and choose a checkout line based on the numbers of people waiting at each register, and the number of items in their baskets. (The single-file ‘banker’s lines’ relieve us of some of this decision-making.)
But the grocer is also making choices based on the Ideal Free Distribution, as to the distribution of products on her shelves. A product that is producing higher profits—the grocer’s ‘nourishment,’ as it were—will enjoy expanded shelf presence, and one with lower profits will contract, or even disappear from the shelf completely.
For example, the average American consumes only 14 pounds of cereal per year, but we eat over 50 pounds of fruit, 200 pounds of meat, and even 125 pounds of potatoes. Likewise, we consume less than 50 gallons of soft drinks in a year, but over 125 gallons of milk. And yet, most grocery stores dedicate an entire aisle to cereals, and another to soft drinks. The reason for this is that breakfast cereal and soft drinks have obscene markups. Both are made from cheap agricultural products costing a few pennies per unit, which then retail for anywhere from one to four dollars, or more. So the shelf space is based on profits rather than stock movement. With time, profits vs shelfspace should adjust, and will tend to match the Ideal Free Distribution.
Stock Market Choices
Investors make these sorts of economic choices in the stock market: high-performing stocks attract more investors until the price vs earnings tend to balance out, and vice versa. Of course, the investor does not completely match the Ideal Free Distribution, because she is taking into account other considerations, particularly risk. To minimize risk, the prudent investor diversifies, and also includes low-yield but low-risk bonds and metal investments. Within each risk tranche, however, the investor is still pursuing the Ideal Free Distribution, trying to maximize returns.
In fact, almost everything the shrewd investor is doing is trying to anticipate what is about to happen, how that will shift the Ideal Free Distribution and investors with it, and how she can use that information to generate profit. In the stock market, however, the Ideal Free Distribution is not really based on the actual worth of a company, at least not the worth in the long run. The market moves around perceived worth because, of course, all of the other investors are also trying to make money off of the Ideal Free Distribution, and are trying to anticipate where everyone else will move.
Flying Buttresses & the Hip Joint
One of the more impressive examples of the Ideal Free Distribution, however, lies in the architecture of the hip joint. Look at the picture here, showing the beautiful flying buttresses inside the adult hip. They look as if an engineer had designed them.
The fact is, we believe that there is no design within them whatsoever: there is no architect, neither Divine nor deoxyribonal. Instead, inside of all of our bones are osteoblasts, bone-making cells which lay down a hard, calcium-based chemical structure; and osteoclasts, bone-dissolving cells, which break down those same hard structures. Between them, they are responsible for the fine little lines making up the buttresses, called trabeculae, as well as for the relative heft of the bone that forms the hard periphery.
So far as we know, these two groups of cells are not following any pre-determined pattern. Although the general outline of each bone is genetically determined, everything else appears to be a result of the Ideal Free Distribution, except that rather than responding to resources, bone cells are responding to need. The osteoblasts move into areas where the trabeculae are experiencing increased forces, and lay down more bony material along the stress lines. The osteoclasts move into areas of decreased stress, and rasp down the bony material, or remove it altogether.Thanks to Dr. Bjorn Olsen for his input on this passage. He reminded me that the contours of our bones are genetically determined, and I edited this post to correct the mistake.
They work quite quickly; after only a few days in space, astronauts show measurable bone loss. After a month in orbit, they can lose 5% of their bone strength. In a 6-month tour aboard the International Space Station they can lose 30%, which is about the same as we see in older women with osteoporosis.
For an ecological theory of sexual dimorphism, click here.
Complexity from Binary Choices
The activity of the osteoclasts and osteoblasts is reminiscent of T.H. White’s description of an ant’s binary thinking in The Once and Future King. White suggests that the ant has only two thoughts, ‘Done,’ or ‘Not done.’ With those two minimalist questions, however, the ant creates its fabulous nests. In this case, however, the ants do not distribute themselves according to resources, but according to need. By constantly bypassing anything ‘Done,’ and moving onto anything ‘Not done,’ ants will congregate around the largest and most pressing tasks in the nest.
In a similar way, the ‘thinking’ of our bone cells is ‘Overused’, and ‘Underused’. With only those two univerbal considerations, cells ignore areas where there is no work, i.e., where the structure is adequate for load-bearing, and invest their efforts in those areas where the bone is either most, or least, stressed. The result is these graceful buttresses. They are as lovely as those in the greatest cathedrals of Europe, and as complex as anything an engineer might design.
Ideal vs Reality
More complex, actually. The flying buttresses of the cathedrals are designed to be ‘ideal’, that is, they are ideal to our minds: they are simple, elegant shapes. If an engineer designed them using structural formulas, he might also design simple, elegant shapes, something like the Eiffel Tower, or the Gateway Arch of St. Louis.
However, those graceful, engineered shapes only approximate what is needed to support a cathedral or some other massive structure. In contrast, the trabecular buttresses inside the hip do not appear to be so perfect, simple, nor elegant. This is because they are more perfect: they are better-designed than the cathedral. We forget, the ideal is an attempt to approach reality, and not vice versa. The hip represents a response to reality, which is messy, unpredictable, and non-ideal. Precisely because the bone trabeculae do not conform to a mathematical or schematic ideal, and precisely because they are not as elegant to our minds, they are more efficient, and more useful for the task at hand.
For this reason, engineers have begun adopting a biological, real-world approach for designing products. The aircraft industry has begun using ‘biomimicry’ to design things like a ‘bionic partition’. Programmers and engineers design software programs, which in turn design aircraft parts. Those parts more closely and efficiently counter the actual stresses on an airplane. Of course, these sophisticated biomimicry models are still based on idealizations of our best solutions.
In comparing the load-bearing structure of the hip joint to the solutions of biomimicry generated by computer programs, two insights emerge. First, the computer programs are extremely complex, while the behavior of the bone cells is very simple. From this, we can see that a very complex solution can result from very simple ecological and economic imperatives.
But second, and critical for our considerations moving forward, we often construct complicated models, explanations, even rationalizations, around what may really be a simple biological imperative. The complex computer solutions are a powerful metaphor for our human rationalizations. We do not want to believe that, at times, we are responding to ancient, simple drives. We prefer to believe in our logic, in our intelligence, and in our sophisticated explanations.
We prefer arguments that prove that we are more than than the animals. But to solve problems, we need to be clear about what is really going on. As we will see throughout these essays, however, the evidence suggests that we are often doing just what animals, and all living things do.
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