Hull et al. Nature 2015

The Collapse of Ecosystems

Douglas H. ErwinDept of Paleobiology, National Museum of Natural History

Smithsonian Institution, Washington DCAnd

Santa Fe Institute, Santa Fe, NM

Biological Classification

Body Fossils

Body Fossils

Marine invertebratesDurably Skeletonized

Geographically WidespreadLong Timespan

Bad Things Happen (fast)Things Get Better (slowly)

New Things Happen

Sepkoski Phanerozoic Diversity

Sepkoski 1999

Bambach, 2006, Ann. Rev Earth & Planet Sci

Bambach’s 18 Mass Extinctions

Mass Extinctions are Rapid

GSSP

Jin et al. 2000, Science

Species Stratigraphic Ranges at Meishan

Rapidity of Mass Extinctions

Sepkoski 1999

< 32 k.y 5 k.y.

< 20 k.y.

Primary vs. Secondary Extinctions

• What % of the total diversity loss was due to primary extinctions vs. secondary extinctions?

• If most extinctions were secondary, then the trigger may be less important than network structure and other biological factors

Bad Things Happen (fast)Things Get Better (slowly)

New Things Happen

Recovery patterns from models

Linear

Logistic

Hyperbolic

Sole et al. 2010 J Theor Biol

Sole et al. 2010 J Theor Biol

Bad Things Happen (fast)Things Get Better (slowly)

New Things Happen

Origination bursts mostly follow mass extinctions for marine genera

Sepkoski 1999

Exceptions

Post-Mass Extinction Diversifications

Ji et al. 2016 J. Vertebrate Paleo

Found in South China, Utah, British Columbia, Spitsbergen

Cartorhynchus Spathian, S. China. Motani et al. 2015 Nature

Icthyosaur Phylogeny

Nesbitt et al. 2017 Nature Benton et al., Earth Science Reviews 2013

E D Jarvis et al. Science 2014;346:1320-1331

Bambach, 2006, Ann. Rev Earth & Planet Sci

Bambach’s 18 Mass Extinctions

‘Missing’ extinctions

Regnier et al 2009 Conservation Biology

Major Themes

• Biodiversity crises have been ubiquitous throughout the Phanerozoic, at many scales

• Collapse is generally fast, recovery slow

• The temporal duration of past mass extinctions is similar to the projected duration of anthropogenic global warming

• New clades do not appear in the fossil record as the recovery progresses, but some evidence suggests that they may have originated pre-crisis

Hull et al. Nature 2015

Hull, Darroch, Erwin, 2015 Nature

Mass Rarity

Origin of New Clades

Crisis(Novelty Formation)

Appearance of New TaxaOpportunistic Ecosystems

Taxa DiversificationInnovation

Ecosystem ’recovery’