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Late Ordovician mass extinction: 445-444 Ma Global cooling and sea level drop, and/or global warming related to volcanism and anoxia [43] Cambrian: Cambrian–Ordovician extinction event: 488 Ma: Kalkarindji Large Igneous Province? [44] Dresbachian extinction event: 502 Ma: End-Botomian extinction event: 517 Ma: Precambrian: End-Ediacaran ...
Ceballos pointed to the extinction of the passenger pigeon, which was the only species in its genus, as an example of how losing a genus can have a cascading effect on a wider ecosystem.
An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms .
The impact of the Capitanian extinction event on marine ecosystems is still heavily debated by palaeontologists. Early estimates indicated a loss of marine invertebrate genera between 35 and 47%, [15] [16] while an estimate published in 2016 suggested a loss of 33–35% of marine genera when corrected for background extinction, the Signor–Lipps effect and clustering of extinctions in certain ...
In the 1980s, Jack Sepkoski identified the Triassic-Jurassic boundary drop in biodiversity as one of the "Big 5" mass extinction events. [1] After the discovery that the Cretaceous-Palaeogene extinction event was caused by a bolide impact, the TJME has also been suggested to have been caused by such an impact in the 1980s and 1990s.
Fortunately, “it’s actually not that hard to simulate a mass extinction,” said Emily Sessa, a plant systematist at the New York Botanical Garden in the Bronx. That’s exactly what her team ...
The idea of extinction periodicity has been criticised due to the fact that the hypothesis assumes that most or all extinction events have the same cause, when evidence suggests that extinctions are likely the result of a variety of causes that are unlikely to be cyclically induced. [8]
Reinforcement can also occur in single populations, [29] [23] mosaic hybrid zones (patchy distributions of parental forms and subpopulations), [31] and in parapatric populations with narrow contact zones. [33] Population densities are an important factor in reinforcement, often in conjunction with extinction. [23]