Mass extinctions past and present: a unifying hypothesis

  title={Mass extinctions past and present: a unifying hypothesis},
  author={S. A. Wooldridge},
  journal={Biogeosciences Discussions},
  • S. Wooldridge
  • Published 9 June 2008
  • Environmental Science
  • Biogeosciences Discussions
Abstract. Enzymes are often referred to as the "agents of life" – a very apt term, since essentially all life processes are controlled by them. Typically, these enzymes only function across a narrow band of environmental conditions, particularly temperature and pH. Ambient conditions that challenge these operating conspecifics trigger enzyme dysfunction. Here, it is proposed that the pH-dependent inactivation of a single enzyme, urease, provides a unifying kill-mechanism for at least four of… 

Figures from this paper

Thinking about the Biodiversity Loss in This Changing World

Extinction of species has been a recurrent phenomenon in the history of our planet, but it was generally outweighed in the course of quite a long geological time by the appearance of new species,

Responses of Stress-Tolerant Corals to Ocean Acidification

of a dissertation at the University of Miami. Dissertation supervised by Professors Peter Swart and Chris Langdon. No. of pages in text: (129) Increased atmospheric pCO2 is expected to reduce coral

Interactive comment on "Mass extinctions past and present: a unifying hypothesis" by S. A. Wooldridge

Thankyou to the reviewers who have posted comments in response to the paper. These comments help to clarify the necessity for formal testing of the urease hypothesis before it can be totally accepted

The environmental disaster of Aznalcóllar (southern Spain) as an approach to the Cretaceous–Palaeogene mass extinction event

The dramatic consequences of the K-Pg boundary impact and the generalized long-time recovery interpreted after the event could have been overestimated due to the absence of a high-temporal resolution in the range of 10(2)-10(3) years.

Species‐specific responses to climate change and community composition determine future calcification rates of Florida Keys reefs

This study demonstrates how species composition influences reef community responses to climate change and how reduced CO2 emissions can limit future declines in reef calcification.

Astrovirology, Astrobiology, Artificial Intelligence: Extra-Solar System Investigations

  • P. Shapshak
  • Physics
    Global Virology III: Virology in the 21st Century
  • 2019
This chapter attempts to encompass and tackle a large problem in Astrovirology and Astrobiology: coming to an understanding of the plurality of extraterrestrial intelligence is an optimal objective, in order to avoid causing harm on exoplanets, as well as avoiding conflict and possible human devastation.

Paleoamerican Occupation, Stone Tools from the Cueva del Medio, and Considerations for the Late Pleistocene Archaeology in Southern South America

Archaeological excavations at the Cueva del Medio performed during the 1980s and 1990s yielded an important record of both faunal and stone tool remains, as well as data, to discuss issues that



The interaction of body temperature and acid-base balance in ectothermic vertebrates.

  • R. Reeves
  • Biology
    Annual review of physiology
  • 1977
Sir Joseph Barcroft began his 1934 volume Features in the Architecture 0/ Physiologi­ cal Function (9) with two essays illustrating Claude Bernard's dictum: "La fixite du milieu interieur est la

Selective Pressure on the Allantoicase Gene During Vertebrate Evolution

Cloned and analyzed comparable cDNA sequences of different organisms from ascidians to mammals suggested that a certain amount of purifying selection is acting on the allantoicase sequences, suggesting the preservation of an apparently unnecessary gene in higher vertebrates.

Paleophysiology and End-Permian Mass Extinction

The end-cretaceous mass extinction in the marine realm: year 2000 assessment

  • G. Keller
  • Environmental Science, Geography
  • 2001

Heart urchins at the Cretaceous/Tertiary boundary: a tale of two clades

  • C. Jeffery
  • Environmental Science, Geography
  • 2001
Analysis of a taxonomically standardized, phylogenetically framed data set demonstrates that the generic extinction rate for heart urchins was 33%, and that the two constituent orders suffered markedly different fates, explaining the differential fates of holasteroids and spatangoids at the end of the Cretaceous.

Benthic foraminifera across the Cretaceous–Tertiary (K–T) boundary: a review

  • S. Culver
  • Geography, Environmental Science
  • 2003

Supramolecular assembly and acid resistance of Helicobacter pylori urease

The crystal structure of H. pylori urease is determined and provides a novel example of a molecular assembly adapted for acid resistance that, together with the low Km value of the enzyme, is likely to enable the organism to inhabit the hostile niche.