Difference Between Background Extinction and Mass Extinction (With Table)

The term “extinct” refers to an organism that no longer lives anyplace in the world. The usual extinction rate is referred to as background extinction. These are species that become extinct since not all life on this planet can be supported, and certain species just cannot exist. Mass extinction is a worldwide occurrence that eliminates the vast majority (more than half) of all living organisms.

Background Extinction vs Mass Extinction

The main difference between mass extinction and background extinction is that background extinction is a gradual and slow process, whereas mass extinction is a sudden and rapid process. According to the history of the Earth, background extinction occurs more frequently, but mass extinction is not very frequent.

The nature of background extinction is gradual and slow, and it is very common in the history of the Earth. The causes of background extinction are direct, and they include the introduction of a new predator or the species’ failure to adapt. The number of species that go extinct through background extinction is higher, and one such species includes the Australian Megafauna.

The nature of mass extinction is sudden and rapid, and it is not very common in the history of the Earth. The causes of mass extinction are indirect and include natural catastrophes or drastic climate changes. Comparatively, fewer number species go extinct through this process, and one such example includes the Dinosaur species.

Comparison Table Between Background Extinction And Mass Extinction

Parameters of Comparison

Background Extinction

Mass Extinction

Nature of Extinction

Gradual and slow

Sudden, rapid, and on a large scale

Frequency of Occurrence

Very common in the planet’s history

Not very common

Causes of Extinction

Direct causes (new predator, failure to adapt)

Indirect causes (natural disasters, climate change)

Number of Species

More number of species go extinct through background extinction

Less number of species go extinct through a mass extinction

Examples of Species

The Australian megafauna went extinct this way

The dinosaurs went extinct this way

What is Background Extinction?

Background extinction is the gradual process through which a small fraction of species at any given moment become extinct over the duration of the planet’s history. Some experts believe that background extinction is caused by deteriorating reproductive fitness and decreased ability to adjust to environmental changes.

The capacity of an animal to create viable children who can live long enough to produce fertile offspring themselves is referred to as reproductive success. Traits that improve an organism’s chances of survival will be prioritized.

Those traits that are detrimental to an organism’s survival will be eliminated in a population. Species at risk of extinction are those in which organisms fail to reproduce or fail to reproduce sufficiently. If a species’ capacity to produce viable offspring in its habitat declines over time, it may go extinct. This is typically how background extinction occurs.

Climate change and invasive species penetration appear to be the primary factors implicated in background extinction. Species will continue to exist as long as their habitat remains within boundaries that they can effectively adapt to.

If the environment changes in such a way that it surpasses these boundaries before a species has time to adjust, individuals of that species will have a more difficult time surviving and reproducing.

What is Mass Extinction?

A mass extinction occurs when an event causes three-quarters or more of current species to become extinct in a geologically short period of time, often hundreds of thousands to millions of years. Mass extinctions are geologically abrupt and usually entail a number of occurrences.

Geologists and paleontologists think that over the last 500 million years, there have been at least five significant mass extinctions. These mass extinctions are significant because they are used to denote key geological timescales eras.

The Mesozoic Era began 251 million years ago with the Permian-Triassic mass extinction and ended 66 million years ago with the Cretaceous-Tertiary mass extinction, which eliminated dinosaurs and ammonites, among other creatures.

So yet, the only mass extinction that has been definitely attributed to an alien object is the one that wiped off the dinosaurs. An asteroid impact with Earth just before the mass extinction event, striking what is now the Yucatan Peninsula on the southernmost edge of the Gulf of Mexico.

The Cretaceous-Tertiary mass extinction was most likely triggered by the impact and flood basalts that produced what is now known as the Deccan Traps in contemporary India.

Main Differences Between Background Extinction And Mass Extinction

  1. The nature of the process of background extinction is gradual and slow, but the process of mass extinction is very rapid and sudden.
  2. The process of background extinction is very common, and the process of mass extinction is less common.
  3. The causes of background extinction are direct, and they include the failure to adapt or a new predator. The causes of mass extinction are indirect, and they include natural causes like disasters and climate changes.
  4. Relatively more species go extinct through background extinction, and fewer species are prone to mass extinction.
  5. The Australian megafauna went extinct through background extinction, and the Dinosaurs went extinct through a mass extinction.

Conclusion

Background extinction occurs when a species’ reproductive fitness declines as a result of environmental changes. Changing climate or the addition of a new predator are examples of such changes. Background extinction is slow and gradual, yet it is common, with only a small fraction of species drifting towards extinction at any particular period during Earth’s history. 

A mass extinction occurs when 75 percent or more of a species dies in a geologically short period of time as a result of catastrophic events. Mass extinction is typically caused by many catastrophes occurring at the same time that overwhelm the biosphere, resulting in catastrophic die-offs.

Background extinction and mass extinction are comparable in how they both include the extinction of species on the basis of environmental changes. However, they vary in that background extinction is a long and steady process, whereas mass extinctions are geologically quick and devastating.

References

  1. https://www.jstor.org/stable/3514632
  2. https://pubs.geoscienceworld.org/sepm/palaios/article-pdf/4/3/243/2848760/243.pdf