Which part of the living system did you change?
Labs / Biology
Island Biogeography
New species keep paddling out from the mainland while species already on the island keep dying out. Drag the island closer or farther, resize it, and add a land bridge — the balance point between arrivals and losses (S*) is the number of species the island can hold.
Labs / Biology / Island Biogeography
Island Biogeography
New species keep paddling out from the mainland while species already on the island keep dying out. Drag the island closer or farther, resize it, and add a land bridge — the balance point between arrivals and losses (S*) is the number of species the island can hold.
Why it matters
Why explore this?
Living systems are connected and constantly changing. This model makes one biological process visible so you can test how its parts affect one another.
Explore
Try the model
S 6S* 0colonized 0extinct 0
Investigate
Questions to test
Predict first, try it in the model, then use what you observe to answer.
What to try
- Slide the island far out to sea. Why does the immigration line sag, and where does S* end up?
- Shrink the island to a speck. Which curve moves, and what happens to the extinction rate?
- Can you find a near, tiny island and a far, huge one that hold the same number of species?
- Flip on the land bridge. Why does connecting to the mainland push S* higher on both counts?
- The species count keeps twitching even at equilibrium — if arrivals equal losses, why is the list never the same species?
Explain
Make sense of what happened
Explain the process as a chain: a change happens, the system responds, and that response affects what happens next. Use an observation from the model as evidence.
Check
Before you leave
How did the system respond?
How would you explain that response?
If you can answer all three using evidence from the model, you understand the main idea. If not, return to Explore and change one setting at a time.