Smedes APES 2.3

What is island biogeography?

The study of ecological relationships and community structures on islands

What are the two basic rules or observations of island biogeography:

1. Larger islands support more total species

2. Islands closer to the “mainland” support more species

What are colonizers?

Organisms that move to the mainland to take up space

What are factors of larger islands?

1. Higher ecosystem diversity

2. More available niches

3. Larger pop. Size

4. Lower extinction rate

What is the type of correlation between island size and species richness?

Positive correlation

What happens when an island is closer to the mainland?

There is higher species richness

Why is there higher species richness closer to the mainland?

• Easier for more species to migrate to the island from mainland (swim/fly)

• More continual migration of individuals to the island

What does frequent migration do?

Brings more genetic diversity and larger pop. size

What type of relationship does island distance and species richness have?

Inverse relationship: the further away from the mainland the fewer species

What is an inverse relationship?

When one factor goes up (distance), the other goes down (biodiversity)

What factors effect evolution on an island?

Resources and limited space

What is adaptive radiation?

Single species rapidly evolving into several new species to use diff. resources and reduce competition

What is an example of adaptive radiation?

Galapagos finches

• Different beaks quickly evolve to fit a variety of different food sources on the island