Every morning in Miami, our fieldwork begins the same way. Fresh Cuban coffee and pastelitos – delicious Latin American pastries – fuel our team for another day of evolutionary detective work. Here we’re tracking evolution in real time, measuring natural selection as it happens in a community of Caribbean lizards.
As an assistant professor of ecology and evolution at Georgia Tech, my journey with these remarkable reptiles has taken me far from my London roots. The warm, humid air of Miami feels natural now, a far cry from the gray, drizzly and lizard-free streets of my British upbringing.
Our research takes place on a South Florida island roughly the size of an American football field – assuming we’re successful in sidestepping the American crocodiles that bask in the surrounding lake. We call it Lizard Island, and it’s a special place.
Here, since 2015, we’ve been conducting evolutionary research on five species of remarkable lizards called anoles. By studying the anoles, our team is working to understand one of biology’s most fundamental questions: How does natural selection drive evolution in real time?
Each May, coinciding with the start of the breeding season, we visit Lizard Island to capture, study and release all adult anoles – a population that fluctuates between 600 to 1,000. For the entire summer, female anoles lay a single egg every seven to 10 days. By October, a whole new generation has emerged.
The anoles of Lizard Island, clockwise from top left: Cuban knight anole, Hispaniolan bark anole, American green anole, Cuban brown anole, Puerto Rican crested anole.
Neil Losin/Day’s Edge Prods.
The secret lives of lizards
Anoles aren’t early risers, so we don’t expect much activity until the Sun strengthens around 9:30 a.m.; this gives us time to prepare our equipment. Our team catches anoles with telescopic fishing poles fitted with little lassos, which we use to gently pluck the lizards off branches and tree trunks. Ask any lizard biologist about their preferred lasso material and you’ll spark the age-old debate: fishing line or dental floss? For what it’s worth, we recently converted – we’re now on Team Fishing Line.
Picture yourself as an anole on Lizard Island. Your life is short – typically just one year – and filled with daily challenges. You need to warm up in the Sun, find enough food to survive, search for a mate, guard your favorite branch from other lizards and avoid being eaten by a predator.
Like human beings, each lizard is unique. Some have longer legs, others stronger jaws, and all behave slightly differently. These differences could determine who survives and who doesn’t; who has the most babies and who doesn’t.
These outcomes drive evolution by natural selection, the process where organisms with traits better suited to their environment tend to survive and reproduce more. These advantageous traits are then passed on to…
