Mass Extinction Event
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An Mass Extinction Event is an mass extinction phase (with mass species extinction) that occurs in under 10 years.
- Context:
- It can (typically) occur when the conditions of an ecosystem change faster than its species can adapt.
- It can (typically) result from various factors, including climatic conditions, changes in sea levels, asteroid impacts, volcanic eruptions, and the evolution of new species.
- It can (typically) result in the loss of most of the species present in the ecosystem.
- It can (typically) be an Evolution-Related Event.
- It can range from being a Past Extinction Event to being a Future Extinction Event.
- It can range from being a Proven Extinction Event to being a Predicted Extinction Event.
- …
- Example(s):
- Cambrian-Ordovician Extinction Event (~488 Mya), one of the earliest known extinction events affecting early marine life.
- Ordovician-Silurian Extinction Event (~443 Mya), where almost 60% of marine life was wiped out.
- Late Devonian Extinction Event (~359 Mya), which primarily affected marine life and resulted in a significant loss of coral reef systems.
- Hangenberg Event (~358 Mya), a late Devonian extinction event that caused widespread losses among fish and trilobites.
- Permian-Triassic Extinction Event (~252 Ma), which eradicated ~96% of all marine species and ~70% of terrestrial vertebrate species.
- Triassic-Jurassic Extinction Event (~182 Mya), that led to the dominance of the dinosaurs in the Jurassic period.
- Cretaceous-Paleogene Extinction Event (~66 Mya), which led to the extinction of Non-Avian Dinosaurs.
- Asteroid Impact Event (~66 Mya): Known as the Chicxulub impact, it is widely believed to have caused the Cretaceous-Paleogene Extinction Event.
- Eocene-Oligocene Extinction Event (~34 Mya), which was associated with significant climate changes and resulted in the loss of many marine and terrestrial species.
- Great Oxygenation Period (~2.4 BYA), while not a mass extinction event in the traditional sense, it caused a significant die-off of anaerobic organisms due to the rise in atmospheric oxygen.
- Holocene Extinction Event (present), which is currently ongoing and driven by human activities such as habitat destruction, climate change, and pollution.
- Mass Global Extinction Period: Generic term encompassing various mass extinction events across geological periods.
- Mass Global Extinction Phase: Another term similar to the Mass Global Extinction Period, highlighting phases of significant biodiversity loss.
- ...
- Counter-Example(s):
- Minor Extinction Events, that do not significantly affect global biodiversity.
- Background Extinction, which is measured by a Background Extinction Rate.
- Life Explosion Event, such as the Cambrian life explosion period.
- ... Events, such as host transfer events.
- See: Mass Extinction, Cretaceous-Paleogene Extinction Event, Permian-Triassic Extinction Event, Ordovician-Silurian Extinction Event, Climate Change, Biodiversity, Geological Period, Speciation, Biomass (Ecology), Microbial, Biosphere, Fossil Record, Alpha Taxonomy, Family (Biology), Invertebrate, Vertebrate.
References
2014
- (Wikipedia, 2014) ⇒ http://en.wikipedia.org/wiki/extinction_event Retrieved:2014-9-20.
- An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the amount of life on Earth. Such an event is identified by a sharp change in the diversity and abundance of macroscopic life. It occurs when the rate of extinction increases with respect to the rate of speciation. Because the majority of diversity and biomass on Earth is microbial, and thus difficult to measure, recorded extinction events affect the easily observed, biologically complex component of the biosphere rather than the total diversity and abundance of life. Over 98% of documented species are now extinct, but extinction occurs at an uneven rate. Based on the fossil record, the background rate of extinctions on Earth is about two to five taxonomic families of marine invertebrates and vertebrates every million years. Marine fossils are mostly used to measure extinction rates because of their superior fossil record and stratigraphic range compared to land organisms. Since life began on Earth, several major mass extinctions have significantly exceeded the background extinction rate. The most recent, the Cretaceous–Paleogene extinction event, which occurred approximately million years ago (Ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time. In the past 540 million years there have been five major events when over 50% of animal species died. Mass extinctions seem to be a Phanerozoic phenomenon, with extinction rates low before large complex organisms arose.
Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty. These differences stem from the threshold chosen for describing an extinction event as "major", and the data chosen to measure past diversity.
- An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the amount of life on Earth. Such an event is identified by a sharp change in the diversity and abundance of macroscopic life. It occurs when the rate of extinction increases with respect to the rate of speciation. Because the majority of diversity and biomass on Earth is microbial, and thus difficult to measure, recorded extinction events affect the easily observed, biologically complex component of the biosphere rather than the total diversity and abundance of life. Over 98% of documented species are now extinct, but extinction occurs at an uneven rate. Based on the fossil record, the background rate of extinctions on Earth is about two to five taxonomic families of marine invertebrates and vertebrates every million years. Marine fossils are mostly used to measure extinction rates because of their superior fossil record and stratigraphic range compared to land organisms. Since life began on Earth, several major mass extinctions have significantly exceeded the background extinction rate. The most recent, the Cretaceous–Paleogene extinction event, which occurred approximately million years ago (Ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time. In the past 540 million years there have been five major events when over 50% of animal species died. Mass extinctions seem to be a Phanerozoic phenomenon, with extinction rates low before large complex organisms arose.