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Demographic stochasticity is often only a driving force toward extinction in populations with fewer than 50 individuals. Random events influence the fecundity and survival of individuals in a population, and in larger populations, these events tend to stabilize toward a steady growth rate. However, in small populations there is much more ...
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 ...
The IUCN Red List of Threatened Species by the International Union for Conservation of Nature is the best known worldwide conservation status listing and ranking system. . Species are classified by the IUCN Red List into nine groups set through criteria such as rate of decline, population size, area of geographic distribution, and degree of population and distribution fragmenta
A growing number of scientists believe a sixth mass extinction event of a magnitude equal to the prior five has been unfolding for the past 10,000 years as humans have made their mark around the ...
The largest extinction was the Kellwasser Event (Frasnian-Famennian, or F-F, 372 Ma), an extinction event at the end of the Frasnian, about midway through the Late Devonian. This extinction annihilated coral reefs and numerous tropical benthic (seabed-living) animals such as jawless fish, brachiopods , and trilobites .
Population bottleneck followed by recovery or extinction. A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as genocide, speciocide, widespread violence or intentional culling.
The Lau event was the last of three relatively minor mass extinctions (the Ireviken, Mulde, and Lau events) during the Silurian period. [4] It had a major effect on the conodont fauna, but barely scathed the graptolites, though they suffered an extinction very shortly thereafter termed the Kozlowskii event that some authors have suggested was coeval with the Lau event and only appears ...
The Changhsingian ended with the Permian–Triassic extinction event, the largest mass extinction event of the Phanerozoic Era, when both global biodiversity and alpha diversity (community-level diversity) were devastated. [9]