
There is no question that the Galapagos Islands can be considered the Garden of Eden when discussing the nature of the evolutionary process. They are a living laboratory of biological science. Unfortunately this evolutionary laboratory that Darwin explored in 1835 is in trouble.
It was very disheartening to read seven years ago about an Ecuadorian tanker incident in which 700,000 liters (240,000 gallons) of diesel fuel leaked from a ship near San Cristobal Island, one of the 4 main islands in this remarkable chain. Eleven months after the spill the toll was 15,000 dead marine iguanas.
It was just one more worrisome incident involving the influence of man there, an influence that has afflicted these islands ever since their discovery 400 years ago. Eleven months after the spill the toll was 15,000 dead marine iguanas.
Even more worrisome is the invasive plants, animals and diseases that are stowing away among the growing shipments of food and supplies heading to the islands. These include cottony cushion scale insects that have devastated local citrus trees and animal diseases such as distemper and avian malaria. These are biological agents for which Galapagos and its remarkable inhabitants are not prepared for. Through the year’s dogs, cats, pigs, goats and traffic have devastated indigenous populations who had never before seen a mammal predator or a car. "Species are being overfished; native wood is being used for building and sand is being dug up from beaches to mix in with cement.” Last year the islands saw 173,000 tourists.
“Galapago” is the Spanish word for "tortoise" and the Galapagos Archipelago is known as the home of giant 400 pound tortoises. Early European buccaneers and pirates provisioned their ships with them, keeping them alive for extended periods with minimal care as a source of fresh meat. They were followed to the islands later by whalers and sealers and finally, of course, by settlers.
With settlers came their wrecking crew of rats, goats, swine, dogs and cats who served as a death warrant to a long list of native animals on these delicate oceanic islands. Many of the spectacularly unique creatures of this isolated archipelago are virtually defenseless against our barnyard menagerie. Several races of land tortoises are now extinct which is a terrible loss as they evolved quite differently from one another on each island. One type of land iguana is also wiped out and others are threatened. Hordes of goats are over foraging islands, devouring everything green is sight and eliminating the food supply of indigenous animals and birds and causing erosion. Hogs root out tortoise nests, rats destroy native bird's eggs and dogs and cats prey on anything defenseless. There is also the constant threat of poachers.
The uniqueness of the fauna of the Galapagos bears revisiting as a reminder of how important they are to us and why we must fight to preserve them. Because of their isolation these ancient volcanic remnants allow us to seem a "speeded up" version of the lengthily evolutionary process, one that can become so obscured on continental areas.
Three quarters of the Galapagos’s birds and virtually all its reptiles are unique. They have their own dove, penguin, cormorant and snake. They also have two specialized gulls and the world's only salt-water foraging lizard, the marine iguana.
A classic example of the complex adaptation that has occurred in one species is that of the Galapagos mockingbirds. Mockingbirds normally behave like catbirds or robins over here but over there they act more like jays, a species they are definitely not related to. In typical jay fashion they do a lot of predation; killing and eating young finches, other bird’s eggs and small lizards.