Generation 1
Small, nearPracticeTap Send colonists.
Run this with a class
Start a class session to get a room code and QR code for students to join. Phones don't need an account. Each phone is given an island type automatically, so the class splits evenly between them. Your browser keeps the instructor key for this room.
Species on each island type
Waiting for groupsSpecies–area relationship
After fumigation: same richness, different species?
Join on your phone
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Scan the code, or go to the address and type the room code. One phone per pair. Each phone gets its own island.
By island type
| Island | Phones | S now | S, last 5 | Turnover | S* | T* |
|---|
"S, last 5" averages the last 5 generations (↑ = still climbing). Turnover = (new species + species lost) ÷ 2 per generation over the same 5 generations; at equilibrium it estimates T*, the rate at which species are swapped. S* and T* are the theory's predictions, shown when "Show the theory" is ticked.
Show every island
| Group | Island | Gen | S | Lost so far |
|---|
Instructor
A new run uses the experiment and rescue setting above, clears this screen and gives every phone a fresh island. The generation limit applies straight away.
Instructor link for another device (keep private)
Anyone with this link can control the room. Students only need the room code.
MacArthur & Wilson equilibrium model
dS/dt = λ − μ λ = I (1 − S/P) μ = E S / P
S* = I P / (I + E) T* = I E / (I + E)
On the phones: I = colonists sent × landing chance (set by distance); E = extinction chance × P (set by island size). The game uses exactly these rules, so the class data should land close to these lines.
Immigration and extinction rates
Each crossing is an equilibrium S*; its height is the turnover T*. Dots show the class's islands, if a run is going.
Filling an empty island
Expected species, starting from an empty island (like Krakatau after 1883, or a fumigated mangrove islet).