This is like an artificially created mass extinction event (e.g. https://en.wikipedia.org/wiki/Extinction_event https://en.wikipedia.org/wiki/Extinction_event )

This is like an artificially created mass extinction event (e.g. https://en.wikipedia.org/wiki/Extinction_event https://en.wikipedia.org/wiki/Extinction_event ). Without it the ecosystem could maintain itself for very long time changing slowly and gradually. An extincting event wipes out most of the existing organisms, creating open niches to be populated with something new and maybe weird-looking.