"Evolutionary" Radiations Don't Match Mass Extinctions

 Report in Popular Mechanics 

The article notes that mass extinctions seem to occur at 27 million year intervals. It also says that evolutionary radiations do not match up well with recovery from mass extinctions! Mass extinctions have been a go-to explanation when asked why organisms change is spurts and then have long periods of stability. This seems to challenge that explanation.

What causes periods of rapid change in natural forms if not mass extinctions with new niches opening up? It seems nature operates independently of the events that naturalists have been saying drive it. So it is something else!