In Praise of Evolution

The never-ending arguments about evolution and creationism (or intelligent design) mystify me. I can’t understand why one of the most beautiful and fascinating aspects of biology is so controversial.

Evolution is all about change, adaptation, and dumb luck. It’s nature’s version of the Las Vegas crapshoot. It’s exciting, and sometimes scary.

From a biological standpoint, evolutionary changes result from a genetic roll of the dice (every time an egg is conceived) or from mutations (random changes to our genes). Most of these changes don’t mean a thing, a few alter our appearance or increase our risk of disease, and once in a while they give us nature’s version of seven-eleven.

Cancer is a good example of evolution in action. Cancers evolve, and they are a microcosm of the entire evolutionary process. I doubt that anyone would ever argue that cancer is just a theory.

Cancers develop from mutations that change the programming of our genes and the behavior of cells. When doctors treat cancer with chemo or radiation, they destroy the weakest cells, but cells with treatment-resistant genetic mutations survive. That’s natural selection—part of the evolutionary process—and that’s why most cancers eventually return.

The randomness of evolutionary process can be unforgiving or serendipitous. You never know how the dice will roll. A moth born bright yellow becomes easy pickings for a bird. But a moth of a different color may blend in to its surroundings, survive, and pass its lucky genes onto another generation.

A century and a half ago, Charles Darwin noticed how different beaks among Galapagos finches were adapted to different types of food. Birds born with maladapted beaks couldn’t feed themselves and so they died off, whereas birds with beaks suited to a particular island’s food sources flourished.

Segues from one species to another take a long time. Monkeys did not turn into human beings overnight—their evolution occurred through a lot of minor changes over millions of years. That’s a difficult time scale for most people to imagine. After all, many of us have trouble imagining what life was like 100 years ago.

It takes my breath away when I think about how life changes through the evolutionary process. I wish I could see a time-lapse film depicting all the little biological changes in the transition from primates to humans, or how mammals returned to the sea and became whales and dolphins. But the millions of years these changes take make that kind of film impossible.

Don’t ask me why all this happens or how it got started. I’m pretty humble about things like that, and rather than ascribe them to one thing or another, I’ll admit that I just don’t know. I can live with not knowing.

I do believe that the irony in all this is that creationists have also evolved. They’ve evolved from a literal Biblical explanation of life on Earth to the more clever argument of intelligent design. I believe that’s a good example of change and adaptation. Too bad they don’t see their own evolution or appreciate the wonder of how life evolves. I think it’s the greatest show on Earth—maybe not in the heavens, but definitely here on Earth.