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Earth’s Worst Mass Murderers: Oxygen, Volcanoes … and Humans?


For everything on Earth, there has been a season: A time for continents to meet, a time for them to break apart, a time for warming and a time for cooling, a time for life to thrive and species to multiply … and a time for them to get obliterated by global catastrophes. Scientists generally recognize five major extinction events when, in very short order (on a geological timescale, anyway), much of life on Earth was utterly stomped into the fossil record. Here’s a look at the five major extinction events of epochs past, and a glimpse at the sixth one we might be causing right now.




“Late Devonian Mass Extinction,” Natural History Museum

“The Five Worst Mass Extinctions,” Endangered Species International

“Big Five mass extinction events,” BBC

“End-Triassic extinction,” Encyclopedia Britannica

“Table 1: The ‘Big Five’ mass extinction events,” Nature



  1. Oky Bastian says

    the result of nature evolution are still brutish, we consume other beings in order to survives, even plants used to be carnivorous, and they don’t like being eaten. maybe abandon our biological body would be good choice.

  2. Nicholas Davis says

    at least 5 Mass Extinctions documented so far (in accordance to the fossil record)….

  3. ValentinSandner says

    A lot of species consume other beings in order to survive but that is not what we do.
    Firstly we’re not in survival conditions, stop killing sharks wouldn’t make our lives tougher. Stop killing whales either, or dolphins, or orcas, or wolves, or bears, or snakes, or frogs, or seals, or pinguins, etc…
    Secondly we don’t just eat other species, we also create conditions in which these species can not survive, even tho we don’t consume them (ie : pinguins).

  4. paul_padyk says

    ElizKolbert WorldSciFest
    Just finished 6th Extinction Brilliant fusion of science for the common man Thankyou!

  5. JohnKwok says

    IMHO Elizabeth Kolbert’s “The Sixth Extinction: An Unnatural History”, is the best popular science book published this year. She does a wonderful job comparing and contrasting current biodiversity loss with those of the five great mass extinctions (terminal Ordovician, terminal Devonian, terminal Permian, terminal Triassic and terminal Cretaceous); most of these were recognized by paleontologists and paleobiologists for decades, based on the work of pioneering invertebrate paleontologist Norman D. Newell of the American Museum of Natural History. In the late 70s and early 80s, invertebrate paleontologists J. Joseph “Jack” Sepkoski and David M. Raup – originally of the University of Rochester, then the University of Chicago – where they “founded’ what would be dubbed the “Chicago School of paleobiology” – applied sophisticated statistical analysis and mathematics – including Fourier Analysis – to measure the tempo of these extinctions, giving us the high estimates of biodiversity loss noted in the graph. Nearly four years ago, a multidisciplinary team of paleobiologists, ecologists, botanists, and zoologists headed by  University of California, Berkeley vertebrate paleobiologist Anthony Barnosky – in a study that was originally a graduate seminar exercise convened by Barnosky and his students – published a paper in Nature showing that current biodiversity loss extinction rates are as high as those of the five recognized mass extinctions in the fossil record. (Since they he and his colleagues, including noted ecologist James H. Brown of the University of New Mexico, have continued tying in current extinction rates with those of the mass extinctions in the context of suggesting means of greatly reducing biodiversity loss. For additional details, look here under publications: http://ib.berkeley.edu/labs/barnosky/.

    On a more personal note, I have retained interest in this despite being out of the field for years, having been trained in both invertebrate paleobiology and evolutionary ecology in graduate school. I hope the World Science Festival thinks seriously of convening a panel at next year’s festival, including the likes of Barnosky, Brown and others.

  6. JohnKwok says

    Paleontologists and paleobiologists have been studying the differences between “normal” background extinction rates and those during mass extinctions for decades. One notable researcher is University of Chicago invertebrate paleobiologist David Jablonski, a former colleague of Jack Sepkoski (deceased) and David Raup (now professor emeritus). Late last summer, the journal Conservation Biology published a notable paper by ecologist Stuart Pimm and his colleagues looking at background extinction rates without relying on the fossil record: http://onlinelibrary.wiley.com/doi/10.1111/cobi.12380/abstract

  7. JohnKwok says

    As for the graph of taxonomic diversity in the Phanerozoic Eon (approximately the last half billion years of Earth history, including the present) drawn by Julie Rossman, it is an updated version of the graph which was published in one of Jack Sepkoski’s seminal papers back in the late 70s and early 80s.

  8. RobertCallaghan says


    I like the part in Kolbert’s book about how biology professors were the last to accept the disappearance of frogs.
    Barnoski’s new book is way overly optimistic. We live in a time of a confluence of crises that converge and overwhelm society. Experts are like one of the three blind men feeling different parts of an elephant and then prescribing solutions to solve the problem of the elephant in the room. The next book I’m going to read is  Ecoside. I read Ward’s, Under A Green Sky. 
    Here is a good video on mass extinction:


    Franz Broswimmer:


  9. RobertCallaghan says

    solar and wind are the bic lighters of the environmental phenom
    billions of toxic exotic minerals that need continual replacement for part-time energy
    we have to go green thorium-solar urban-rural permaculturist
    using carbon gas tanks as batteries for clean fuels instead of lead
    no more flying to climate conferences to do nothing

    100% private carbon taxes no share for governments & corporations
    A new world e-carbon currency phase in to eliminate national boundaries
    tie organic food into currency worldwide to kill Monsanto before they kill us
    circumvent corporate government quickly
    or gm trees may be all that survives us
    unless our food eats us first .)

  10. RobertCallaghan says

    the oil, nuclear and green energy people are all lying to us. we have to use thorium to clean up uranium waste and provide the base power green energy needs, power down, power honestly, ultimately we will have to combine green energy, thorium and permaculture. thank you for replying .)

  11. RobertCallaghan says

    god like power and base instincts
    we were designed to get here
    time to grow up and unite the world

  12. JohnKwok says

    RobertCallaghan , at best what you propose won’t solve the ongoing problem of severe biodiversity loss, nor is it really relevant to comparing and contrasting what we know from the mass extinctions recognized within the Phanerozoic Eon (approximately the last half billion years of Earth’s biological history, including the present) with the present, “Sixth Extinction”. Conservation biologists like E. O. Wilson – a previous World Science Festival participant – have proposed meaningful solutions which Kolbert mentions. As for dealing with our carbon addiction, back at the 2009 World Science Festival, NASA climatologist James Hansen reminded us that we would have to adopt nuclear power as the most credible, most realistic, alternative.

  13. RobertCallaghan says

    JohnKwok good work! 1000 10000, who cares? diamonds maybe for heifers, but extinction is forever

  14. JohnKwok says

    RobertCallaghan, for us to understand the differences between extinction rates during “normal” times and those during mass extinctions, we need to examine the differences between background extinction and mass extinction rates. As I noted several days ago, David Jablonski, has made notable contributions to our understanding in distinguishing between these two types of extinctions.

  15. RobertCallaghan says

    Mass Extinction Manifesto
    solar-wind-batteries are the bic lighters of the environmental phenom.
    billions of tons of toxic exotic minerals that need continual replacement for part-time energy.
    we have to go green thorium-solar urban-rural permaculturist.
    using carbon-fiber gas tanks as batteries for clean fuels instead of 
    billions of tons of heavy toxic lead, liquid metal or molten salt batteries.
    no more flying to climate conferences to do nothing in a wired world.
    We need centralized thorium type power to clean up uranium and provide 
    the clean base power renewable energy needs to grow clean, not green.

    100% private carbon taxes no share for governments & corporations.
    A new world e-carbon currency phase in to eliminate national boundaries.
    tie organic food into the currency worldwide to kill Monsanto before they kill us.
    circumvent corporate government quickly.
    or gm trees may be all that survives us.
    unless our food eats us first .)

    Mass Extinction Vs. Green Energy (watch extinction video)

  16. JohnKwok says

    RobertCallaghan, as a former invertebrate paleobiologist, I don’t need to watch the video. I think you are missing my point – and one that is emphasized by Elizabeth Kolbert in her book “The Sixth Extinction: An Unnatural History” – that we need to rely on the scientific research done by paleobiologists and ecologists in trying to deal with our ongoing severe biodiversity loss. One of the key chapters in Kolbert’s book deals with the species-area curve that’s been studied by ecologists for decades, and noting the importance of setting aside sufficient territories for animals and plants to survive. This research inspired Robert MacArthur and E. O. Wilson to develop their theory of island biogeography, which is the fundamental scientific theory behind modern conservation biology.

  17. RobertCallaghan says

    JohnKwok yep spect ur right, corridors and conservation are great, although pressures mount to ignore conservation areas by the resource mafia,  meat prices should include carbon taxes to reduce consumption. spect nuthin’s gonna work in time, doesn’t mean we don’t try though, good luck, i’m just a guy who cuts grass who’s got two cents to spare

  18. JohnKwok says

    RobertCallaghan, no the “pressures” you speak of pertain largely to the non-Western world in which vast tracts of forest and grassland have been eliminated for both human settlement and agriculture. That’s where the problem lies, and paying “carbon taxes” may have little or no impact.

  19. JohnKwok says

    @RobertCallaghan, no, your observations ignore the fact that much of the loss in biodiversity is due to overfishing, and other human activities such as destroying forest and grassland habitats for human habitation and agriculture, especially throughout much of the non-Western world. And then, too, is the impact of global warming on declining biodiversity loss which Kolbert notes with regards to ocean acidification.


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