The Slow Fade: Background vs Mass Extinction

If extinction happens at a slow and steady pace due to natural competition or local changes, then it is considered the standard background rate of species loss.

If a background extinction only affects a few species at a time but a mass extinction wipes out more than half of all life on Earth quickly, then the mass extinction is clearly faster and more destructive.

If a catastrophe occurs that kills off the majority of living groups across the globe, then the number of individual species remaining drops significantly.

If a species cannot find enough food because another animal is better at hunting, then that species might slowly die out. If this is a normal part of nature, then it is a cause of background extinction.

If a disaster is global and affects every habitat at once, then it can cause a mass extinction; however, local events like one animal eating another only contribute to background rates.

If background extinction happens constantly every day for billions of years, then it actually accounts for the majority (about 95%) of all extinctions in history.

If we look at the fossil record and see five specific times where the majority of life disappeared suddenly, then there are five major mass extinction events.

If a species dies out because its specific forest was cut down, then the extinction is local (background). If species are dying on every continent and in every ocean at the same time, then it is global (mass).

If background extinction is a constant part of the "circle of life," then it is always occurring at a slow rate due to natural biology; it does not happen in huge, sudden bursts.

If a mass extinction destroys almost all the branches on the "Tree of Life," then it takes a very long time for the survivors to evolve and fill those empty spaces again.

If the layers of rock show a sudden disappearance of many types of bones and shells, then we are seeing a mass extinction in the fossil record.

If an animal is perfectly evolved to live in a forest but an asteroid suddenly burns the whole forest down, then its "fitness" didn't matter. If the disaster is too big to survive, then it is a matter of bad luck.

If the change is slow or only affects one specific area or food chain, then it is a background factor. Asteroids and global volcanoes are mass extinction triggers.

If human activity is killing off species 1,000 times faster than the normal background rate, then the current loss of life is large enough to be considered a new mass extinction.

If an event was so severe it earned the nickname "The Great Dying," then it occurred at the end of the Permian period.

If background extinction only kills one species, then a "twig" is gone. If a mass extinction kills a whole group of related animals (like all dinosaurs), then a whole "limb" of the tree is removed.

If a global disaster hits, then being widespread and flexible with food helps you survive. In background extinction, being a strong fighter (A) might be enough, but that doesn't save you from an asteroid.

If an extinction event (either type) involves species dying out, then the total variety of life (biodiversity) must go down before it can eventually go back up.

If the rate is what we expect to see during "normal" times without any giant disasters, then it is defined as the background rate.

If some extinctions are slow and constant while others are huge and rare, then the lesson is that species loss occurs at different scales and speeds throughout history.