02/13/2013 04:57 pm ET Updated Apr 15, 2013

Natural Selection and the Up-Goer Five Text Editor

Like many of you, I bit on the Up-Goer Five Text Editor. I marveled at "Hamlet" in the ten hundred most common English words. Jumping in, I took the challenge. Could I explain the theory of evolution via natural selection using only the thousand most used words in English?

After several tries, this is what the Up-Goer Five Text Editor allowed me to say,

MR. DARWIN and MR. WALLACE had a good idea. They said, if living things of the same kind are different from each other even in small ways, and if the small worlds these living things live in are sometimes different so that some living things of the same kind -- because of the ways they are different -- have more babies or live longer than other living things of the same kind, and if children are like their parents, the living things of the same kind can change over time and become new living things.

"Too Dick and Jane for me!" exclaimed my kind husband. "It's gobbledygook" announced my childhood friend, the literary scholar and author, Justine Tally. What follows is a slightly edited version of my email "do-over" for Justine.

Herewith is a deconstruction of the gobbledygook of the Dick and Jane version of the theory of evolution via natural selection that Darwin and Wallace independently discovered. Natural selection is a hypothetico-deductive statement (hypothesis), by which I mean it is constructed of a series of first principle assumptions, like the proofs in geometry. (If all the assumptions are true, then the deductive inference must be true). In Up-Goer Five lingo: if this is so, and this is so, and this is so, then this new thing must also be so. Remember all those geometry proofs in high school? They are what I mean by hypothetico-deductive statements with the added advantage that they "could be proved" by measuring each assumption in a plane. Hypotheses of natural selection are like plain plane geometry, like arithmetic, in fact.

There are four assumptions in Darwinian statements of evolution via natural selection. The first assumption is about who carries heritable variation. It could be individuals within a population, or individuals within a sex within a population, or it could be whole populations. Most of us think about variation among individuals within populations (or species). Say, for a specific example, that individuals within a local population use different nesting places with some individuals nesting in tree holes and others in holes in the ground. The second assumption is about what part of the environment varies and affects what happens to the "units" in the first assumption. Say, for a specific example that the climate changes, so that the world gets hotter and wetter with effects on the individuals depending upon where they nest. The third assumption is about the component of fitness that weather affects -- number of babies or whether the individuals themselves survive. Say, for our specific example that individuals in ground nests die when the floods associated with the big rains come, but individuals who nest in trees survive. Then assume that the tree nesting habit is heritable (either via genes or culture or the interaction of genes and culture), so that children resemble their parents and nest in places similar to where their parents nested. In our example the tree nesters survive better than the ground nesters, so that it is likely that the population (or species) will evolve so that individuals only nest in trees. Well, the thing that has just happened is evolution via natural selection, the new thing.

After my exchange with Justine, I spent a long time playing with the Up-Goer Five Text Editor trying to describe the experiences that inspired Darwin and Wallace in the mid-1800s to discover the idea of evolution via natural selection. My unoriginal thesis was that their experiences as natural explorers and intellectual adventurers with wild nature led them to their great theory.

The Up-Goer Five Text Editor was unforgiving and wouldn't let me explain that the great naturalists' experiences were the key to understanding their independent discoveries of natural selection. The ten hundred words of the Up-Goer Five Text Editor didn't include "plant", "mammal", "bird", "fish", "snake", "insect", words that denote enormous differences between kinds of creatures. Even harder to explain was the variation within kinds of organisms - like variation within say a species of snake like Burmese pythons or species of birds like eastern bluebirds - that so impressed Darwin and Wallace, one of the key observations that allowed them to come up with the idea of natural selection. Using only the allowed 1,000 words of the Up Goer Five Text Editor made is very hard -- maybe impossible -- to capture and explain the idea that there is variation within kinds of living things. The Up-Goer Five Text Editor only seemed to allow the Platonic, essentialistic, typological ideal of 'plant" or "animal" from which Darwin's 1859 master-work liberated us.

Had the Up-Goer Five Text Editor had words for concepts of variation, or perhaps had I been more persistent, I would have gone on to link our culture's relative lack of experience with wild -- or even tame -- outdoor nature to the inability of some readers to accept the truth of the theory of evolution by natural selection.

Perhaps some of you will be more successful than I was in using the Up-Goer Five Text Editor to make clear the power of the idea of within-kind variation for the discovery of natural selection. Let me know!