Extinction

Extant taxa

term for taxa that are still alive, not extinct

Extirpation

term for death of the last individual of a population

Extinction

term for extirpation of all populations of a species

Mass extinction

term for the loss of 3/4 of earth's species in a geologically short period of time

Ordovician

443 mya

-86% of species; glacial and interglacial episodes, sea level rise and fall, change in atmospheric and oceanic chemistry

-first major mass extinction event on Earth

Devonian

359 mya

-75% of species; global climate change, anoxic deepwater spreading to shallower water, ultimately we do not know the cause

-extinction event

permian

251 mya

-96% of species; Siberian volcanism and global warming,spread of anoxic marine water, increased concentration of CO2 and H 2 S, ocean acidification

-largest known mass extinction

Triassic

200 mya

-80% of species; Volcanic activity in Central Atlantic Magmatic Province (CAMP) raised atmospheric CO 2 , increasing global temperatures and leading to calcification crisis in oceans

-mass extinction

cretaceous

65 mya

-: 76% of species; bolide impact in Yucatan resulting inrapid cooling, probably combined with Deccan volcanism, ultimately a shift toglobal warming, eutrophication and anoxia of the oceans

adaptive radiation

An evolutionary pattern in which many species evolve from a single ancestral species

dead clades walking (Theory)

When a clade, or part of a clade, survives a mass extinction but will never reach what it was before the extinction. Often times the clade can not make a full recovery and will extirpate

-eg living fossils; nautilus, coelacanth

sixth extinction

this is an ongoing extinction event of species during the present Holocene epoch, mainly due to human activity.

causes:

1. population

2. consumption

3. climate change