This tab is a patch of land with its own climate. Its creatures eat, breed and pass their traits on. When it gets too crowded, too hungry or too hot or cold, they walk off the edge in search of somewhere better.
Right now there's nowhere for them to go.
Tip: drag the new tab out into its own window and put the two side by side, so you can watch creatures walk across.
Opens a second tab. Closing a tab is an extinction.