Population of green iguanas lived on a tropical island. Originally, most of the iguanas had feet without webbing between their toes and a long round tail. A few iguanas had webbed feet and a short, flat tail. As the years passed, the island became smaller and smaller because of flooding. Even the land areas were dotted with ponds and pools. The iguanas had a hard time finding the food they normally ate. To survive, the iguanas had to swim from island to island to find food.
