Imagine: Millions of years ago, volcanic eruptions spewing hot lava and ash created the Galapagos Islands.  They are barren.  There is no grass; there are no trees; there are no animals.  However, all the islands now have plants and animals, even the very newest.  Where they came from and how did they survived once they reached land is the story of Colonization.

Living organisms can only reach a new island by crossing the body of water from the place where they were before.  This is true whether it is just a short trip from a nearby island or when over a million years ago plants and animals form distant South America fist colonized the Galapagos chain.

Crossing water is difficult for both plants and animals.  They are exposed to the bright sun for days and have no fresh water or food.  Still, only a few make it… a special few.

Plants came first to the islands.  They came as seeds, falling unto minute patches of soil where they could grow.  Small seeds were carried on the feet and feathers of seabirds, as well, and even inside the stomachs.  Some smaller seeds were blown to the islands in the wind and larger seeds floated on currents after being washed out to sea.

Once there were plants to eat, animals that accidentally got to the islands could survive.  Insects, like seeds, could have hitchhiked on birds or been blown by the wind.  Large animals, like the sea lions or sea birds, swam or flew on their own.  However others, like iguanas were unwitting passengers on floating logs or mats of plants.  Most land birds were carried by storms to the islands.

Some of the seeds and some of the animals survived and reproduced.  Other animals and seeds never made it on the islands.  In this way, they established new populations isolated from their ancestors on other islands or on the South American mainland.  Now they are thriving, similar to and yet very different from their distant cousins.

There are also about 2000 kinds of animals living in the shallow waters surrounding the islands.  They are like animals found near other Pacific islands and their ancestors also crossed inhospitable deep waters to reach the Galapagos Islands.  However, shallow marine creatures frequently have larvae that float long distances before settling to the bottom.