In Honor of Darwin Day

We are all Keynesians now.

This quote, usually attributed to Richard Nixon, is really believed to have been said by Milton Friedman. What Nixon actually said was “I am a Keynesian in economics now.” Both statements are powerful in the fact that they come from people who are ideologically on the right. They are in  a sense saying the tenets of and evidence for Keynesian economics are so powerful that they are able to sway people who may be ideologically resistant to accepting the theory. I remember my declaration of my Keynesian identity. That came in the fall of 2011. I was taking a macroeconomics course at the time, and the country just had the “natural experiment” of the Great Recession. I remember how much Keynesian theory made sense, fit the evidence, but was also so simple.

It may seem strange to talk about economics and Keynes on Darwin day, a celebration of the life and studies of Charles Darwin. But if it weren’t for Darwin and his (and Wallace’s) theory of natural selection, I would have never become a Keynesian. I would have never pursued academia. Hell, I wouldn’t have ever understood science. That’s because Darwin’s theory of natural selection made me understand what is and isn’t a good scientific theory.

I first truly understood the theory of natural selection when I took a course in ecology and evolution in spring 2009. Before then, I never really understood science. I treated it like a series of facts to be learnt and spit out instead of understand the process. Sure, I had learned the scientific method, but even then, it was more a series of steps understood by my conscious brain. I could write them down, but beyond that, nothing. It was only after learning the theory of natural selection that I could understand its power and the power of a good scientific theory.

Evolution by natural selection is often taught to people in terms of examples. The fastest antelope is able to evade the cheetah, the tallest giraffe gets the leaves, the most extravagant bird gets the mate. Taught this way, it is hard to synthesize what is actually going on. And that’s how  I learned natural selection until spring 2009. It was then that my college professor laid it out in four specific bullet points:

  • Individuals differ in traits from one another
  • Some of these traits are at least partially, if not fully, heritable
  • The traits an individual has can affect the number of offspring it has (its fitness)
  • An individual’s environment determines its fitness

These four points are simple, so simple that a child could grasp and understand how this happens and what is going on. In fact, we can reduce them to just five words: “heritable variation and differential fitness”. 5 words, 4 points and yet more than enough to explain a significant portion of the diversity of life on Earth. I felt like Thomas Huxley – “How extremely stupid not to have thought of that.” When I learned about natural selection like this, I had to declare “I am a Darwinist in biology now”.

From then on in the course, we built up from Darwin’s theory, learning in detail the peculiarities of how evolution worked about the strange and interesting dynamics that could come from it. Natural selection (along with some genetics) formed the backbone of what we know about the diversity of life today. It was the steel structure in our tower of knowledge. Everything flowed easily and seamlessly from it, nary a hic-cup or bump slowing it down. So much power from so simple a beginning idea. It was then I realized how to determine the validity, the “truth” of a scientific theory. Was it simple, blindingly intuitive, and yet able to explain an enormous amount of evidence? Then it must be — on some level — true. That’s what made me a Keynesian, that’s what made me a Darwinist, and that’s what made me understand science.

Darwin shaped me in many ways. Learning about him and other scientists like him solidified my love ecology, evolution, and natural history. They made me want to pursue a career in academia. Because of them, I work at the intersection of ecology and evolution, trying to answer the fundamental questions about the natural world. More than that though, Darwin specifically gave me a way of thinking. It gave me a way of understanding the best tools to answering questions and the best answers to a question. It freed me from the magic tricks that people often do to convince you of bogus theories. It freed me from the mounds of bullshit that plagues us. Darwin gave me a way of understanding the world around me.