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  2. Extinction event - Wikipedia

    en.wikipedia.org/wiki/Extinction_event

    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.

  3. Shiva hypothesis - Wikipedia

    en.wikipedia.org/wiki/Shiva_Hypothesis

    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]

  4. What is a mass extinction, and why do scientists think we’re ...

    www.aol.com/brief-history-end-world-every...

    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.

  5. Beer–Lambert law - Wikipedia

    en.wikipedia.org/wiki/Beer–Lambert_law

    To describe the attenuation coefficient in a way independent of the number densities n i of the N attenuating species of the material sample, one introduces the attenuation cross section = (). σ i has the dimension of an area; it expresses the likelihood of interaction between the particles of the beam and the particles of the species i in the ...

  6. Anoxic event - Wikipedia

    en.wikipedia.org/wiki/Anoxic_event

    Another way to explain anoxic events is that the Earth releases a huge volume of carbon dioxide during an interval of intense volcanism; global temperatures rise due to the greenhouse effect; global weathering rates and fluvial nutrient flux increase; organic productivity in the oceans increases; organic-carbon burial in the oceans increases ...

  7. Background extinction rate - Wikipedia

    en.wikipedia.org/wiki/Background_extinction_rate

    There are three different ways to calculate background extinction rate. [5] The first is simply the number of species that normally go extinct over a given period of time. For example, at the background rate one species of bird will go extinct every estimated 400 years. [6] Another way the extinction rate can be given is in million species ...

  8. Global distillation - Wikipedia

    en.wikipedia.org/wiki/Global_distillation

    Global distillation or the Grasshopper effect is the geochemical process by which certain chemicals, most notably persistent organic pollutants (POPs), are vaporized and transported from warmer to colder regions of the Earth, particularly the poles and mountain tops, where they condense.

  9. Permian–Triassic extinction event - Wikipedia

    en.wikipedia.org/wiki/Permian–Triassic...

    Permian–Triassic boundary at Frazer Beach in New South Wales, with the End Permian extinction event located just above the coal layer [2]. Approximately 251.9 million years ago, the Permian–Triassic (P–T, P–Tr) extinction event (PTME; also known as the Late Permian extinction event, [3] the Latest Permian extinction event, [4] the End-Permian extinction event, [5] [6] and colloquially ...