Examining status of 'Big Five' mass extinctions 40 years after discovery

In the marine fossil record, Raup and Sepkoski identified five distinct periods of time when there was a significant amount of species loss, a recent Cambridge University Press report said. This discovery was made more than 40 years ago. These occurrences, which later became known as the "Big Five" catastrophic extinctions, are regularly brought up, especially in light of the current biodiversity situation, which is being referred to as the "sixth mass extinction."

There is no statistically significant difference between the Big Five and the baseline extinction rate—while other time periods, such as the Cambrian and early Ordovician, had higher extinction rates. As a direct consequence of this, there is a contentious discussion on the historical periods that ought to be referred to as "mass extinctions." In spite of this, even in analyses that seek to take into account the limitations of the fossil data, the Big Five are still considered noteworthy occurrences. Although the factors that led to a great number of mass extinctions have been investigated, the unpredictability of the natural environment and the temporal holes in the geological record make it difficult to get a better understanding.

Despite the high extinction rate and relatively low number of extinctions, there is still time to prevent the current biodiversity catastrophe from becoming a genuine mass extinction. This is the case even if the number of extinctions has been relatively modest. In light of the fact that the designation of the Big Five is entirely discretionary, the term "incipient Anthropocene mass extinction" would be a better alternative to "sixth mass extinction."