Endemism

As a final part of our note card assignment, I have an important theory in evolutionary biology to discuss that is extremely relevant to the Galapagos Islands. The topic I have to discuss is endemism...which I probably should have described first without using it in previous posts! As we have already discussed in our pre-departure meetings, an endemic species is a species that is found only in one place in the world--nowhere else. How large can this place be? We're not talking about continents here; we're talking about a species that is found on one specific island, or one particular country, or one habitat zone in a country. That being said, since they are only found in one region of the world, endemic species are prone to extinction, either from competition or human intervention, since by definition endemic species are relatively rare. How do endemic species rise about? There are two ways. In paleoendemism, the population of a formerly common species shrinks to the point where the species can only be found in one area--this is essentially near-extinction. By contrast, in neoendemism, a new species arises through speciation and reproductive isolation. Knowing what we know about the Galapagos--the volcanic islands have never connected to the mainland and are thus ripe for adaptation, speciation, and evolution--we can expect to find a large number of endemic species in the islands. This is part of what makes this trip so exciting! We'll see things that people cannot see anywhere else in the world.

I hope you've enjoyed this bite-sized series on animals and plants found in the Galapagos! I'll be sure to take my own pictures of these things and share them with you all.