Extinction: How Life on Earth Nearly Ended 250 Million Years Ago

Extinction: How Life on Earth Nearly Ended 250 Million Years Ago

by Douglas H. Erwin

Some 250 million years ago, the earth suffered the greatest biological crisis in its history.

Around 95% of all living species died out--a global catastrophe far greater than the dinosaurs' demise 65 million years ago.

Here, the world's foremost authority on the subject provides a fascinating overview of the evidence for and against a whole host of hypotheses concerning this cataclysmic event that unfolded at the end of the Permian.

Erwin reviews the evidence for each of the hypotheses before presenting his own view of what happened.

Although full recovery took tens of millions of years, this most massive of mass extinctions was a powerful creative force, setting the stage for the development of the world as we know it today.

  • Language: English
  • Category: Science
  • Rating: 3.83
  • Pages: 320
  • Publish Date: February 1st 2006 by Princeton University Press
  • Isbn10: 0691005249
  • Isbn13: 9780691005249

What People Think about "Extinction: How Life on Earth Nearly Ended 250 Million Years Ago"

memorized, you will find yourself getting lost at times when he uses the late part of an era or period synonymously with a stage. and another adds additional evidence suggesting that one of the potential "killers" may be more likely the culprit than previously suspected: http://www.reuters.com/article/2014/0... Even with the new research however, it seems that the author is likely right that it was not one culprit acting totally alone, but more likely a chain reaction in which one culprit catalyzed the actions of another, perhaps even several others.

That said, the read, given that it's what we have, by the what is probably the foremost expert on the Permian extinction, is worthwhile because he takes the time to delve into WHY the things most likely responsible for the planetary near-death experience 252ish million years ago are in fact the culprits. (And arguments that volcanism may have been at least partly responsible for killing the dinosaurs as well as 75% of life on earth are coming again to the fore.) So, Erwin goes into all that. So, here we are today, loading the atmosphere with carbon and because we've spread species around the world, and reduced diversity... If we're in the middle of a Permian-level extinction, it's too late to stop it, so he says we might as well assume we're not and that we can reverse the current trend. Because as I said in my recent reviews of other, related books by friends of Erwin's, it's not just climatologists who are worried about climate change, or this era of human participation in the history of life on earth.

That apocalyptic event occurred approximately 252 million years ago, at the Permian-Triassic (PT) boundary, and it wiped out nearly 95% of all living species on Earth. In his book, Extinction: How Life Nearly Ended 250 Million Years Ago (New Jersey: Princeton University Press, 2006), Smithsonian palaeontologist and curator, Douglas Erwin, investigates the current data and the resulting hypotheses that seek to explain what happened. After gaining the readers attention with that unusual admission, Erwin then focuses on the reason these rocks are so boring by describing the nature of the end-Permian mass extinction event that will be investigated throughout the book and providing a glimpse of the available evidence. Erwin also discusses important evidence gathered from both terrestrial and marine sediments, and along the way, the reader will learn the significance of a variety of studies, including; using ammonoids, conodonts and other ancient species to define the structure of the PT boundary; the presence of a putative fungal spike in the early Triassic, soon after the PT boundary, also; obtaining radiometric dates using zircons obtained from volcanic ash beds; and the shifts in carbon isotope ratios, along with sulfur and strontium isotope data. In Resurrection and Recovery, the author describes patterns of biotic recovery, noting that early Triassic fossils were dominated by a few opportunistic (weedy) species and states that it took more than 4 million years before there was a demonstrable increase in speciation in the fossil record. Further, this book does more than simply offering an account of the latest knowledge surrounding this mysterious mass extinction, it does a great job revealing how scientists think about complicated issues and the evidence that supports differing hypotheses.

Near the end, he briefly discusses whether or not the massive die-off determined which species survived long term and eventually led to the current diversification of life or if the ones hardest hit by the destructive event(s) had already been in decline.

The author presents a well written book providing the known facts(as of 2006) which he uses to develop the accepted theories which try to explain the Permian-Triassic extinction. This is not an easy read but it was interesting to learn how paleontologists work, investigate and develop theories.

Even though the book is now 10 years old (2006) and precedes the discovery of methanosarcina, I though it might shed some light on this extinction and of course Im also trying to tie this extinction to the possible current mass extinction. This isnt quite fair to Erwin and actually there are other parts of the book which are more or less comprehensible. Thats when a species seemingly goes extinct during some mass extinction event, and then millions of years later, suddenly reappears in the fossil record. Thats what Erwins main interest is not so much the mystery of what caused the end-Permian extinction, but the mystery of how (or whether) this event really affected the evolutionary process in a fundamental way.

The book tackles the biggest mass extinction in the fossil record - about 250 million years ago. Early on, the book goes over the fossil record basics and the main competing theories explaining why it happened. The book's title makes it sound like it's targeted for a general audience.