A Familiar Refrain

Abstract

When I was a child, I lived near Kennedy Space Center in Florida. To me, science was all about rocket science: big rockets that flew where no one has gone before, powered by fiery oxidative chemistry and guided by precise measurements. I could watch the space shuttle go up, and trust it would come down, connecting Earth’s orbit to the ground at my feet. That we could send hollow metal capsules on such immense journeys was a wonder I never quite got over, not even when two of the shuttles failed to return home. I had a different view of evolution. It seemed messy, haphazard, cruel, and wasteful, nothing like the sleek engineered rockets at the Space Center. Most of all, I think it just seemed boring. Why study the unpredictable? To be sure about something, you need to see it work multiple times, right? I missed the chance to see evolution work multiple times, right in my home county. In the next lagoon over from where I once dredged up sulfurous muck for my science projects, on six small islands, the tape of life was being replayed six separate times. All six times, it gained the same result. Evolution might be messy, haphazard, cruel, and wasteful, but it is also predictable. In 1995, scientists brought Cuban brown anole lizards to six small islands in Mosquito Lagoon, which only had green anole lizards at the time. Each time, scientists watched what happened and compared the results to five nearby islands that remained green-lizard-only zones. After three years of competition, the green lizards changed their behavior and perched twice as high in the trees. In 2010, the scientists returned and examined the lizards’ feet. On the invaded islands, the green lizards had larger toepads with more wrinkly lamellae than on the non-invaded islands. This difference in feet was mirrored by differences in the lizards’ genes. In a 15-year span, the lizards evolved. (During the same time span, my opinion of evolution also evolved, as I learned about a chemical order behind the biological messiness.)