[Scarblac]

The problem is that beavers didn't suddenly start doing that, the ecosystems they live in co-evolved around the existence of beavers.

On time scales relevant to evolution, human civilization is happening in an instant and nothing can adapt as fast.

The result is a gigantic loss of biodiversity.

[refurb]

Bacteria can mutate quite quickly and wipe out an entire species pretty fast, reducing biodiversity.

[saagarjha]

Can they wipe out thousands of species?

[frutiger]

Yes: https://en.m.wikipedia.org/wiki/Great_Oxidation_Event

[MiyamotoAkira]

Wait, that says it took around 0.3 billion years, and when there was only single cell life, we have no clue about the biodiversity at that point in time. It cannot compare in time scale, and we have no clue if it can compare on biodiversity scale.