I found this WWW page with the Google: https://en.wikipedia.org/wiki/Extinction_vortex https://en.wikipedia.org/wiki/Extinction_vortex It's a boundary below wh

I found this WWW page with the Google: https://en.wikipedia.org/wiki/Extinction_vortex https://en.wikipedia.org/wiki/Extinction_vortex It's a boundary below which specific feedback mechanisms accelerate extinction, fragmentation of populations being one condition.