Species arrival to the GALáPAGOS
When the Galapagos Islands first appeared above the ocean’s surface about 8 million years ago, they were devoid of life. The two main methods of island colonization are by air and by sea, followed by human introduction in more modern times. The spores of ferns, mosses, and lichens were likely carried to the Galapagos from the South American mainland by wind, as were many small insects. Small birds were also likely aided by wind, and larger seabirds simply flew to the islands. Much of the Galapagos’ other wildlife arrived by sea. Some animals, such as sea lions and penguins, are/were strong swimmers and probably swam their way to the Galapagos. Small mammals and reptiles, on the other hand, likely floated to islands on rafts of vegetation, and some salt-tolerant coastal plant seeds also floated over. These methods of transport would explain why there are few flowering plants, no amphibians, and many reptiles- reptiles and non-flowering plants are better adapted to the stresses of colonizing a remote island.
It’s amazing that all of the wildlife in the Galapagos has only been there for a relatively short period of time. It’s also astounding to think of how many rafts of vegetation with animal hitchhikers there must have been for some to have survived and made the ~1000 km journey. These methods of colonization are incredibly unlikely to be successful, yet they occurred so many times that the necessary species made their ways to the island, leaving us with the wildlife we see there today.
It’s amazing that all of the wildlife in the Galapagos has only been there for a relatively short period of time. It’s also astounding to think of how many rafts of vegetation with animal hitchhikers there must have been for some to have survived and made the ~1000 km journey. These methods of colonization are incredibly unlikely to be successful, yet they occurred so many times that the necessary species made their ways to the island, leaving us with the wildlife we see there today.