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

by Douglas H. Erwin

Book Overview

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. How this happened remains a mystery. But there are many competing theories. Some blame huge volcanic eruptions that covered an area as large as the continental United States; others argue for sudden changes in ocean levels and chemistry,...

• Format: Hardcover
• Language: English
• ISBN: 0691005249
• ISBN13: 9780691005249
• Release Date: February 2006
• Publisher: Princeton University Press
• Length: 320 Pages
• Weight: 1.23 lbs.
• Dimensions: 1.1" x 6.0" x 9.3"

Customer Reviews

Splendid agnosticism

In Kentucky, there's a museum with a lifesize model of a dinosaur with a saddle on it. This is a hymn in fiberglass to young Earth creationism, the idea that the Universe was created about 6,000 years ago. It costs $1,500 to become a charter member (family rate) of this museum. A much better investment would be $24.95 for Douglas Erwin's thriller about the Permian extinction. More than nine-tenths of all species died out 251 million years ago. Erwin, a researcher with the Smithsonian Institution's National Museum of Natural History and the Santa Fe Institute, finds the end-Permian "enigma far more compelling than the end of the dinosaurs," a relatively minor event from 65 million years ago. For an event that Kentuckians think never happened, the end-Permian event left a lot of debris, of which the most interesting is in China. Until 20 years ago, the paleontological record there was unknown to the outside world. What the evidence is telling us is difficult to say. Erwin says "Extinction" was "frankly written as a mystery story." In this one, the clever detective does not wrap up all the loose ends on the last page. Instead, we learn that there are at least seven major theories of what might have happened. These range from a big meteorite to gigantic volcanic eruptions in Siberia to a climatic or biological or geological change that drove oxygen out of the oceans. The first chapters set the stage. Life was very different in the Permian. There were reefs in warm oceans, and they contained corals, but the corals were only distantly related to those of today and they were not as important as crinoids and lampshells, animals that still exist in out-of-the-way places. On land, flowering plants had not yet evolved, nor mammals, dinosaurs or saddles. In South Africa's Karoo basin, fossils remain of a fabulous, lost fauna. There were widespread extinctions on land as well as in the sea during the end-Permian event, but it is hard to say whether the land extinction was as complete as in the sea, where 94 percent of species disappeared in a short time. Erwin's team and their Chinese collaborators have found evidence that it all happened in less than 160,000 years -- maybe a lot less. It is also not proved that the big land extinction exactly coincided with the sea kill, but it seems likely. The land kill was a whopper, too. This was apparently the only time in history when a mass extinction had any real impact on insects. Whatever the cause, it did set up the modern world. "Mass extinction is a powerful creative force," says Erwin. Or did it? As they learn more and more of the details, scientists are also learning to question the easy assumptions of more innocent decades. Evolutionary biologists are vigorously debating whether the animals and plants that dominated the Permian were already being outcompeted by the early forerunners of modern flora and fauna, or whether they would have maintained their control of resources. Erwin, splendidly agnostic about th

The Ultimate Whodunit: The End-Permian Mass Extinction

Reading this book gave me the same sort of headache that reading Paul Gallico's THE POSEIDON ADVENTURE did -- I kept stumbling and wincing over badly puncutated sentences, mis-applied terminology, and a host of other stylistic and grammatical problems probably due to the fact that instead of properly proofreading this first edition work, somebody relied on a spell-checker to do the whole job and ignored everything else. That said, however, like THE POSEIDON ADVENTURE as well as Gallico's other work -- and like the work of Ceremonial Magickian Aleister Crowley, essentially an engineer writing for other engineers who would be able to fill in the blanks and make mental corrections of technical boo-boss as needed, not for a public who neither know nor care about the nuts and bolts of the Magickal aspects of reality -- I couldn't put the damned thing down. Like Gallico, Erwin has a powerful sense of story, far and away THE essential ingredient of a great literary work, and what is paleontology all about, anyway, but the study of the long, long story of Earthly life? He also has just as powerful a sens of humor, as well. And his analysis of the problem and possible avenues to its ultimate solution -- an understanding of what caused the End-Permian catastrophe -- is meticulous, painstaking, and fascinating. A wonderful read. I hope that by the time the paperback version comes out the editorial problems will have been corrected -- but even if not, I'll buy it anyway. This is a must for the library of anyone who has any interest at all in the history of living creatures, their tenure on Earth, and what their story has to tell us about our own probable futures. I give it five stars, though maybe with half a point off for the editorial stuff.

Do it again, Erwin

I am in the process of reading this book and am very pleased. I have some background in geology and paleontology but still found the introductory materials interesting and informative without being simplistic. It is very unusual for a distinguished scientist to admit that he - or we - don't know what happened in the Permian extinction, and to invite the reader to develop theories of his or her own, but that is what Erwin has done, and sucessfully. Do it again, Erwin, with all the other extinctions. You may get a lot more people thinking.

Resetting the clock

Any scientist who opens [and closes!] a book by saying "We [I] don't know!" is worthy of your attention and respect. Too many others have taken up a theme and defended against all comers. Erwin's examination of the catastrophic close of the Permian Age is complete, admirably researched and exquisitely written. Within its pages, this work examines the various ideas on the massive loss of life 250 million years ago. These days, not to have heard of an meteor's killing off the dinosaurs 65 million years ago suggests you've lived hidden in a cave for a generation. Erwin opens with a brief overview of that event, reminding us that extinctions, particularly "impact events", have loomed large in discussions of the history of life ever since Walter and Luis Alvarez proposed the idea. It's easy to rattle off the numbers: when the dinosaurs "went West", perhaps 75% of life was also extinguished. When the Permian ended, over 95% of living things disappeared. Erwin asks: "How do we know this? What life forms disappeared? Did they all go at the same time? How long did it take to recover?" Most important, of course, "What killed them off?" Instead of dull statistics, Erwin asks the important questions. Acknowledging that "Triassic rocks are boring", he explains why this is so. Fossils are scarce is the obvious answer, but why they are missing is his quest. With most of his attention focussed on ocean life, he details what causes shifts in benthic populations. The seas rise and fall - for a variety of reasons. Glaciation takes up sea water and leaves continental shelves high and dry. Oceans need to "turn over" an oxygen supply. What is the result of that failing? Carbon, with its various isotopes, passes through life selectively. Tracing that path provides insights into where it's been - and where not. When did the Siberian "traps" form? How much lava spewed from that rift, and what other products did it bring along or destroy? Finally, is there evidence that Earth was pelted by another bolide to provide an easy answer to all those questions? That reply is almost surely negative. Erwin would like to couch this narrative as a detective story, but it doesn't really work. There are too many victims - unless you count life as one entity. There is also a phalanx of detectives all trying assiduously to solve the case. If you thought there were too many cooks spoiling the broth, wait until you meet this mob. Nearly all of them have an agenda and they have a disturbing tendency to trumpet a single tune. Erwin should have portrayed them as an orchestra, with himself as conductor. Van Kariajan would go emerald with envy. Each investigator supplies a theme, striving for a solo performance. Erwin cautiously assesses the tune, fits it nicely into a grander theme and produces a symphony instead of a cacophony. It's quite a performance. To keep himself from the sin of hubris, he points out his own flaws in a previous effort. The strai

When Life Almost Didn't Make It

Even kids now can tell you about the mass extinction that wiped out the dinosaurs. When I was a kid, the dinosaur extinction was a big mystery, but there has been good evidence, now broadly accepted, that 65 million years ago a meteor as big as a mountain smashed into the Yucatan, turning everything for miles around into ash, wrapping the world in a cloud, and blocking the sunlight that runs all life. Everything all over the world changed, and we mammals got our try at reproductive success. The horrendous extinction that ended the Cretaceous age, however, wasn't the worst our old Earth had seen. 250 million years ago, there was an extinction that ended the Permian and began the Triassic periods (which is also the border between the larger, more general Paleozoic and Mesozoic eras). This Permo-Triassic event extinguished around 95 percent of all living species, and was as close as we have ever come to having all life wiped out. In fact, in the 19th century, geologists thought that life had been wiped out and a separate creation had occurred to start the Triassic. What really happened, and how, are the subjects of _Extinction: How Life on Earth Nearly Ended 250 Million Years Ago_ (Princeton University Press) by Douglas H. Erwin, Senior Scientist and Curator of the Department of Paleobiology at the Smithsonian. He has made the end-Permian mass extinction his research interest for the past twenty years, and has traveled all over the world to the fossil beds and geologic boundary layers remaining from around the time of the catastrophe. Looking back so many millions of years ago is not easy, and the picture is not as clear as that of the dinosaur extinction. Erwin's book, however, is a fine demonstration of how geologists and paleobiologists have come to some admittedly limited understanding of what happened. There are many factors that have been suspects in the great killing, and Erwin likes to think of himself as a detective out of Agatha Christie set to finger the actual culprit. It's not that easy, of course. Catastrophic explanations for the end-Permian abound, and Erwin's book is an examination of the more likely causes, about six of them. Of course, a main one, borrowing from the success of the impact explanation of 65 million years ago, is an extraterrestrial impact. It is certainly a plausible explanation, since it is accepted as the cause of the more recent extinction. There are problems, however. The impact that wiped out the dinosaurs left clues like an iridium layer in geological strata (there is lots of iridium in meteorites, not so much on Earth) and "shocked quartz" impact crystals, but such clues are lacking for the earlier event. Another explanation might be volcanism, resulting in dust and acidic chemicals and basalts that cover a countryside "much as honey fills in the roughness of an English muffin." Yet another is that continental drift (plate tectonics) was causing collisions at the time, forcing species that