This definition above refers to the geographic isolation.
It means exactly what it says in the definition - one species is left behind from the rest of the population, and it stays in that particular location, evolving and changing from the species and population it was once a part of.
A mass extinction event occurs when a species disappears far more quickly than it is replaced. This is typically understood as the loss of around 75% of all species over a "short" period of geological time, or fewer than 2.8 million years.
An enormous number of species were wiped out by a harsh, worldwide, swift, and selective event is mass extinction. According to marine fossils, at least 75% of all species are thought to have become extinct. The most recent mass extinction is the Cretaceous-Paleogene extinction event, which is also the only one that can be proven to have been caused by a significant asteroid impact. All non-avian dinosaur species, making up about 76 percent of all species on the earth, perished during mass extinction. The Chicxulub asteroid impact in what is now Mexico, which occurred 66 million years ago, caused an ecosystem collapse that resulted in the extinction of the dinosaurs and >75% of all land and sea species as well as the macroevolution of mammals.
Learn more about mass extinction
brainly.com/question/11872946
#SPJ4