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Organisms and Environments

Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America

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As recently as 11,000 years ago—"near time" to geologists—mammoths, mastodons, gomphotheres, ground sloths, giant armadillos, native camels and horses, the dire wolf, and many other large mammals roamed North America. In what has become one of science's greatest riddles, these large animals vanished in North and South America around the time humans arrived at the end of the last great ice age. Part paleontological adventure and part memoir, Twilight of the Mammoths presents in detail internationally renowned paleoecologist Paul Martin's widely discussed and debated "overkill" hypothesis to explain these mysterious megafauna extinctions. Taking us from Rampart Cave in the Grand Canyon, where he finds himself "chest deep in sloth dung," to other important fossil sites in Arizona and Chile, Martin's engaging book, written for a wide audience, uncovers our rich evolutionary legacy and shows why he has come to believe that the earliest Americans literally hunted these animals to death.

As he discusses the discoveries that brought him to this hypothesis, Martin relates many colorful stories and gives a rich overview of the field of paleontology as well as his own fascinating career. He explores the ramifications of the overkill hypothesis for similar extinctions worldwide and examines other explanations for the extinctions, including climate change. Martin's visionary thinking about our missing megafauna offers inspiration and a challenge for today's conservation efforts as he speculates on what we might do to remedy this situation—both in our thinking about what is "natural" and in the natural world itself.

250 pages, Hardcover

First published January 1, 2005

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About the author

Paul S. Martin

78 books1 follower
Paul Sidney Martin was an American anthropologist and archaeologist.

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Profile Image for Peter Tillman.
4,057 reviews483 followers
May 10, 2023
I first read this book in 2006 after I heard the author give a talk at the venerable Desert Lab in Tucson. Martin was pretty venerable by then, too -- but still razor-sharp. His thesis is that Early Man in the New World killed off the Pleistocene megafauna -- mammoths, ground sloths, giant armadillos -- by overhunting. This was controversial then, and probably still is.

OK, now to tackle my 10 3x5 cards of notes! The extinctions and local extirpations that followed the spread of early humans are well-documented, and they were worst where the animals were least familiar with human hunters: the New World. Strongest contrast is Africa, where there were (ims) NO extinctions as modern humans evolved, as the prey animals had time to adjust. Not true after modern humans developed firearms!

Martin knows North America best, and writes eloquently about the loss of the big animals, mostly not long after Clovis people arrived from Asia around 12,000 or 13,000 years ago. Our megafauna was at least as rich as old Africa, and South America was richer still, with even stranger animals. Armadillos the size of VW beetles! 3 genera of elephants! Ground sloths as big as elephants! -- the sloths, sadly, the first to go extinct. Easy meat for the well-armed Clovis hunters.

It would be well-worth the time of any interested reader to visit a large natural history museum and spend a few hours in their Hall of Mammals -- such as the newly-renovated one in Los Angeles. You'll see creatures a LOT less familiar than the dinosaurs....

And I should mention Martin's puckish humor, and cool photos of his youthful self. He relates a visit to the Bat Cave mine in Arizona, https://en.wikipedia.org/wiki/Bat_Cav... -- after he saw a headline in TIME magazine about "Giant Meat-eating Bats!" discovered there. NOT -- but quite a trip, and it initiated him into Grand Canyon cave exploration, which became a major part of his career. Ground sloths were involved, and TONS of sloth dung: he comments on a colleague who "really knew his sloth shit".

The part of the book that a lot of people didn't care for was his "rewilding" proposals at the end, including me on my first read -- but these actually make sense. Martin criticized the misguided burro-killing Park Service at Grand Canyon, as the burros had pretty close relatives here until extirpated by those hungry Clovis guys. As were all the horses! Just imagine if the Incas and Aztecs had had cavalry forces to fight the small Spanish invasion. Might have changed history!

It is *very* surprising that no Clovis people figured out horses, before they ate them all -- as it didn't take the Sioux, Cheyenne, etc. etc. any time at all to tame the wild Spanish horses they captured -- which had escaped & multiplied *very* quickly, as they were re-occupying a vacant eco-niche from their local extirpation maybe 11,000 years before. So these were genuine wild animals, albeit previously selected for taming. But, still -- they were originally tamed in the Old World from wild stock....

READ THE BOOK. OK? It will change your life! (maybe). Paul Martin's masterwork!

For background, https://en.wikipedia.org/wiki/Paul_S....
RIP 2010.
Author 32 books34 followers
April 13, 2014
This is the classic text promoting the theory that hunting by early human beings was responsible for the extinction of large animals in North and South America, Australia, Oceanic Islands and elsewhere. The late Paul S. Martin (who died in 2010) intended this book to be his legacy volume, and although its scientific basis has been altered by subsequent research, it remains far from outdated, and provides an inspirational call for human restraint, and for environmental restoration.
The essence of Martin’s argument is that many species of large mammals (collectively known as megafauna) disappeared from planet Earth at almost exactly the same time that human beings first migrated onto the continents of their disappearance. Martin, who spent a long career as a research paleo-ecologist at the University of Arizona, did most of his research on North America, although this book also makes reference to South America, Australia, New Zealand and other places. 13,000 years ago, North America was teeming with mammoths, mastodons, large species of bison, woodland musk ox, large deer, and the lugubrious ground sloths, some of which were as large as elephants. 10,000 years ago, all of these large animals and many others were extinct. Not coincidentally, human beings were thought to have entered North America from Asia, across the Bering land bridge, approximately 12,000 years ago. (The exact date is subject to argument, and that influences the megafauna extinction hypothesis).
In Twilight of the Mammoths Martin describes with humor, warmth, and fervor, his career as a scientist, who primarily studied pollen grains in the mud of ponds and other places, in order to trace historical vegetation types, in order to trace changing, ancient ecosystems. Martin’s career shifted however, when he became the leading specialist in fossil poop. By studying fossilized feces of ground sloths and pack rats, Martin made major contributions to paleo-ecology. His unusual humor and charm as a writer is captured by the moment when he discovers a cave near Grand Canyon filled with ancient sloth dung. He describes himself standing, “chest deep in layers of stratified sloth dung…the air smelled resinous, like incense…one did not need to be a Sufi or a mystic, to sense that this…chamber was a sacred sanctuary.” Much of the delight that a reader can gain from Twilight of the Mammoths stems from an encounter with a scientist of such elevated emotion that a gigantic pile of poop becomes an object of his worship.
A lot of the book consists of more austere argument, or descriptions of discoveries. Martin argues with passion for the hypothesis that overkill, and not climate change or disease, was responsible for the trans-continental megafauna extinctions, because he believed that he was helping to awaken humankind to the need to limit its own potential for destruction. Martin was a distinguished scientist and a passionate participant in engaged science writing.
In this book the author spends a lot of time trying to refute two arguments against overkill. If human beings killed so many animals, why are there so few fossil kill sites? The author struggles to provide a credible answer for this weakness in the data for his hypothesis. If human hunting extinguished large animals, then why did Africa retain its megafauna into the middle of the twentieth century, when Africa has the longest history of human/animal interactions, because it has the longest history of humanity? Martin answers the “African paradox” by asserting that the long co-evolution of humans and megafauna led to increased vigilance on the part of the animals, in contrast to the continents onto which humans migrated relatively suddenly, giving the megafauna little opportunity to learn, evolve, or adapt.
Today, Martin’s overkill hypothesis cannot be embraced in entirety, even by continued advocates for the importance of overkill. Our science today is more nuanced, and we need to think about when and where any one species died out, what it ate, what local and not merely continental climatic conditions were at the time, what was happening to other neighboring species that competed with or preyed upon the species in question, what ecological niches were expanding or contracting, etc. A single over-arching hypothesis is no longer welcomed, because it is too monochromatic.
But Martin’s writing remains important and elegiac. If our science has somewhat superceded his, our environmental situation has deteriorated further towards the one he warned us about and tried to prevent. It is difficult to argue, as some of Martin’s critics do, that human violence is not a major cause of animal extinction, when we think of the right whales, blue whales, the buffalo, all species of rhino, both African and Asian elephants, tigers, cheetahs, manatees, pretty much every large, beautiful mammal.
Some of Martin’s most important thoughts still pertain. For example, he had an expansive and poetic sense of time, and reminded his readers not to be locked inside “the Columbian curtain,” that has us looking at environmental history as if “nature” started in 1492. He reminds us that ecosystems are always dynamic and constantly changing, “multiple stable states or discordant harmonies.” He tells us that he is writing to protect, “the complexity, joy, and the whole way of life,” of mammals and wild lands. He chastises us to remember that Pacific islands lost roughly 8,000 species of land birds after humans conquered those islands and he states emphatically, “extinction has marked the spread of our species.”
Much of this book contains more nuanced arguments about how much and when climates changed, the dates of sloth extinctions, and more technical points that do not always appeal to the general reader. Martin also describes plans for the restoration of wild and semi-wild species, some of which do not seem realistic. Overall however, Martin comes over as a minister of the wild, who takes his text from the great Thoreau, who he quotes as saying, “ I wish to know an entire heaven and an entire earth.” Along with the wonder of the great and prolific beasts who dominated our North American home and made it splendid in mammalian diversity, this book also reminds us to wonder at the murderous ignorance of one expanding, dominant species.

Review by Paul R. Fleischman author of Wonder: When and Why the World Appears Radiant

Profile Image for Bill Chaisson.
Author 2 books6 followers
May 3, 2022
After years of writing scientific papers in the required scientific paper style, Paul Martin was able to relax and deliver an impassioned first-person argument in favor of both his "overkill" hypothesis and his argument in favor of "rewilding" North America. He has addressed lay audiences before, both in person and in magazine articles, but this might be the only book-length jeremiad. Published five years before his death at 82 in 2010, this perhaps serves as a summation of his life's work.

The title and subtitles are a little confusing. Martin devotes a great many more pages to ground sloths than he does to mammoths, but Twilight of the Ground Sloths just doesn't have the same ring. And while Martin focuses most of his attention on the extinctions of the North and South American megafaunas, he also is good about supplying the reader with details about the megafauna extinctions in Australia, New Zealand and Oceania. The Australia event took place ~40,000 years ago and moas disappeared from New Zealand only 500 years ago. He uses the term "near-time" in the book to include all events in the last 50,000 years and that is more accurate than "Ice Age." Finally, he devotes only the final two chapters to the subject of rewilding.

Martin is an amiable narrator and those without a lot of background in geology or evolution should not be shy about picking up this book. He brings along beginners gently by explaining his terms and using a genial writing style that should keep most readers calm in the face of numerous Latin names. He even includes several plates of line sketches that show you what the animals looked like.

His basic argument, which is still controversial, is that extinction events that target large animals during "near time" occur shortly after arrival of Paleolithic hominids. African and Eurasian biota shared the landscape with hominins for hundreds of thousands of years, which allowed the non-hominin biota to evolve behaviors that included avoiding Paleolithic hunters. In contrast, the sudden arrival of humans on continents that had heretofore been hominin-free meant that prey animals had no defense against hunters with stone tools and cooperative strategies. Non-human predators disappeared because of direct killing or starvation due to declines in prey populations.

In addition to coinciding with the arrival of humankind, Martin also emphasizes that all these extinction events included large animals (and smaller animals and plants that were ecological dependent on them). Large animals were targeted, he argues, because they are easier to find and provide more nutrition per kill. In fauna after fauna, Martin shows that the extinction are concentrated at the upper end of the size range, regardless of whether the upper limit was 1,000 or 100 kilograms.

The alternative cause for these extinctions has traditionally been climate, but there is no way for a climate to cull a fauna according to species size. Nor can any climate phenomenon be identified that can explain the transgressive timing of all of these near-time extinction events.

That is the crux of Martin's argument and of his opponents. Over the course of nine chapters, he goes over this disagreement from several perspectives and in various settings, methodically describing the extinction details, his own proposal, the climate-related proposal, and why overkill explains the data better. Although an attentive and/or informed reader may quibble with some parts of his argument, in the main, Martin comes across as a reasonable man who would be willing to concede a point here and there if presented with good data.

His argument for rewilding is less well developed than his explanation for the near-time extinctions. He would like for the government to leave in peace the existing wild horse and burro populations because their ancestors were present on the continent for millions of years, hunted to extinction only 13,000 years ago. Many of the extinct animals, however, left no particularly closely related descendants, so Martin is content to advocate that their close relatives be introduced. For example, he believes dromedary and Bactrian camels are fine stand-ins for Pleistocene camelids, and Rocky Mountain goats are near enough to the extinct Harrington's goat.

He gets pretty far afield though when he argues that oryxes and elands are acceptable substitutes for extinct North American bovids because they occupy a similar ecological niche. Ditto for African and Asian elephants sitting in for the disappeared mastodons and mammoths. It all sounds like a great deal of fun, but also sounds like a pretty hard sell, especially when it comes to the lions and the cheetahs.
Profile Image for Ushan.
801 reviews79 followers
December 27, 2010
Large animals in Africa and tropical Asia have had millions of years to adapt to hominids, but large animals in all the other continents hadn't. When humans colonized Australia about 50 thousand years ago, this was the end of a giant monitor lizard ten times the weight of the Komodo dragon, a rhinoceros-sized marsupial browser, and several species of large kangaroos. When humans colonized the Americas about 13 thousand years ago, the same happened to mammoths, mastodons, gomphotheres (tropical mastodons), several species of ground sloths, several species of camelids and equids, glyptodons (car-sized thick-shelled armadillos with mace-like tails), and other animals. The same happened to moas in New Zealand about 500 years ago and to gorilla-sized lemurs in Madagascar about 1000 years ago; also, in Madagascar, a whole order of mammals as specialized as the pangolins or the aardvarks (Bibymalagasia) was gone. Worldwide, about half of all genera of large terrestrial mammals disappeared. As readers of Jared Diamond or Tim Flannery know, it looks like humans hunted them all to extinction, since the extinctions happened in "deadly syncopation" with the arrival of humans. Paul Martin spent 40 years of his life confirming that this was the case, for example, investigating a deposition of dung of ground sloths and extinct goats in a very dry cave in Colorado. Now, suppose the management of a national park in the Western United States wants to decide, which animals should live in the park. The ones that lived there when Lewis and Clark passed through the area, did not see any goats, but saw goat-hair blankets among the local tribes? Or the ones that lived there at the time of Columbus, before Native Americans got hold of firearms? Or the ones that lived there before the ancestors of the Native Americans came from Siberia? There were equids in America at that time; feral horses and donkeys (mustangs and burros) are now their substitutes. There were also camelids and proboscideans and a subspecies of lion; should Asian camels, elephants and lions be released into the wild? Paul Martin also proposes celebrating Clovis Day to honor the original colonizers of the Americas, which "need not replace" Columbus Day.
Profile Image for Sheryl.
33 reviews
July 8, 2011
I find the idea of repopulating the Americas with relatives of extinct natives to be very interesting. I am not sure it is totally practical, but I can easily see elephants on the plains of Texas. What fun that would be!
1 review1 follower
December 29, 2008
I learned that I am still not positive that the Pleistocene magefauna were killed by Homo sapien but I do want to see Elephants in New Mexico.
Profile Image for ReadingSloph.
1,139 reviews9 followers
April 2, 2022
Lots of good, interesting information. The different categories were good. It gives overview where you can then decide which parts are most interesting to you and then you can go find more information on those different parts.
Profile Image for Michael .
342 reviews45 followers
May 18, 2018
In grade school, one year, I sat next to a dinosaur artist. With apparent ease, he sketched fantastic images of Triceratops, Brachiosaurus, Stegosaurus, Pterodactyl, and of course, T. Rex. From that year on I was hooked on all things dinosaurs.

Not until years later did I become aware of the once abundant and more recently missing megafauna. These large, ice-age mammals mysteriously vanished from the Americas about 13,000 years ago. Big cats like American Lion, American Cheetah, Saber Tooth Cats - gone. The large, formidable Short-Faced Bear - gone. The lumbering Giant Ground Sloth - gone. The American elephants like the Columbian and Wooly Mammoths and the Mastodon - seemingly dematerialized. True, there were a few isolated populations lasting until 1700 BC on remote islands such as Wrangel in the Arctic Ocean.

In North America 74 percent of the mammal genera weighing more than 88 pounds vanished during the late Pleistocene Epoch. And during the same time window, in South America, it was 82 percent. Additionally, the late Pleistocene extinctions eliminated all mammal species, in the Americas, weighing more than 2200 pounds.

What happened? Why just the big, land mammals? Evidence for disease or comet / asteroid impact as the culprit is weak. Based on the geographical distribution of skeletal remains, some of the large animals such as the American Lion and the Columbian Mammoth had a transcontinental range, tending to blunt an argument blaming climate change.

Some people see a deadly syncopation of human colonization with extinctions of the large, probably naive animals. Paul S. Martin, originally a fossil pollen expert, developed the theory of overkill and in North America, he linked the Clovis paleo-indian culture to megafauna extinctions.

Evidence of the hunting methods used by Clovis people are circumstantial, though thought-provoking. Methods may have included effective use of dogs and fire. And use of potent hunting poisons applied to their famous, fluted projectile-points cannot be ruled out.

Dinosaur sketches, modern trophy hunters, popular zoo animals, the appeal of rodeo, and ancient Roman coliseum entertainment all support our natural fascination with large animals.

It's an intriguing topic. Megafauna extinctions, in both hemispheres, impoverished ecosystems on multiple continents. Martin's 2005 book, 'Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America' is an excellent introduction to the clues and provides a thoughtful, whodunit-style solution. Lions, Cheetahs, Bears, and Elephants - Oh My!
Profile Image for Kirsten.
2,137 reviews117 followers
June 21, 2011
Paul Martin paints a fascinating picture of North America 13,000 years ago in this excellent work of non-fiction. Martin is a strong proponent of the idea that prehistoric humans are the cause of the extinction of many of the large mammals that once roamed North America, and he presents compelling evidence for his theory here. The extinction of the mammoths, ground sloths, and other large mammals has often been chalked up to climate change in the past, but Martin believes this is inaccurate. He points out that most of these mammals had already weathered similar climate changes as those that occurred around the time of their extinction. Additionally, the fossil record does not reflect the dying off of plants and small animals that one would expect from such climate change. Most damning is that the extinctions of large mammals worldwide seem to coincide closely with humans expanding beyond Africa: the fossil record indicates that when humans enter an area, extinction soon follows.
This is not a finger-shaking book, however: Martin is not interested in blaming anyone for any kind of political reasons, and while he definitely thinks we should pay attention to the evidence and keep history from repeating itself, he is careful to stress that he is not trying to lay blame for the extinction of the mammoths at the feet of any one group of people.
Part of the book that really fired my imagination was when Martin pointed out that much of the native vegetation of the Americas evolved in the presence of mammals that are no longer native. For example, until 10,000 years ago, horses and horse-ancestors were a huge part of the mammal population. For this reason, Martin does not necessarily see it as a problem to have non-native equines like burros and wild horses roaming our grasslands and canyons: his feeling is that the plants evolved to handle this, and handle it they can. They may even thrive under the influence of reintroduced equines. Basically, he thinks that our view of what kind of wildlife is "native" to the Americas is terribly limited, since we only have about 500 years of recorded history. It's an interesting idea, and I would be really curious to know what our landscape might be like if we still had elephant-relatives roaming around.
Profile Image for Stephen.
1,962 reviews142 followers
January 30, 2016
Speaking of which, I finally finished Twilight of the Mammoths, which I began....months ago. I'd wanted to learn more about the megafauna that dominated the Americas before humans arrived. I'm utterly fascinated by the idea of primitive North America as a land of lions and cheetahs, a wilderness teeming more with large life than even Africa. As it turns out, a primary source for learning about ancient mammalian behaviour is...dung. Dung is mentioned more in Twilight of the Mammoths than it is in Flushed: how the Plumber Saved Civilization. That I mark impressive, but it's versatile stuff, dung. The oh-so-serious dung dissection didn't interact well with my desire to be awed, so my interest trailed off until being reignited by Baxter and Pratchett's The Long Earth, which involves as part of its setting an Earth in which humans never spread to the Americas, and so the native ecology is intact. Twilight exists to argue that human predation ("overkill") was the primary cause of megafauna extinctions in the Americas, as opposed to climate change. In the decades since Martin released this book, I believe overkill has become the standard explanation, but even so this is a worthwhile book for the curious mind. It puts overkill on solid ground for those new to it, provides a catalog of large animals that were driven into extinction, and ends with a smaller argument advocating for the restoration of the prehuman ecology, one using still-living animals to replace the many gaps the spread of human civilization created. He suggests, for example, using camels to counter the spread of mesquite in the southwest.
Profile Image for Frederic Murray.
43 reviews1 follower
December 12, 2013
Who killed all the Megafauna in North America? Looks like we did after crossing the land bridge from Asia som 10,000 years ago...Professor Martin is the go-to-guy in this field, a great scholar, a solid writer.
Profile Image for Ryan.
Author 1 book36 followers
February 14, 2023
It was good to read about the megafauna overkill theory directly from the horse's mouth so to speak. Paul Martin was its original proponent as far back as the 1980s, so I am surprised that this book only came out in 2005, when the author was in his 70s. I suppose it was his magnum opus of sorts, as he had already published numerous papers on the subject over the years, and also aimed at a wider audience outside of scientific circles. The horse analogy is apt, as much ink was spilled over the acceptance of wild asses ('burros') in the American southwest as ecological equivalents of extinct equids of the Americas - the continent of their origin and fifty million year evolutionary radiation.

The writing tended to be rather dry and academic in most chapters, when he talked about particular excavation sites where fossilized mammals or their excrement were discovered and painstakingly analyzed. And since I was already familiar with the reasoning, evidence and premise of overkill, the arguments, while adequate, weren't exactly exciting as they would be to someone fresh to the subject. The nice parts were the long lists of extinct large mammals Martin compiled not just for America but globally, including Madagascar and Australia as well, with accompanying line drawings of representative species; and his eloquent plea for the remembrance and hopefully restoration of the 'near time' megafauna. In this respect, his criticism of the idealization of wilderness in North America as the state Europeans found it to be before colonization as misguided is well founded.
Profile Image for Jeremy.
15 reviews
March 6, 2018
I did not know what I was getting into when I started reading this book, but it certainly was something great. With his work on extinct megafauna of the Americas, Martin opens up a hidden past that would surprise most people today. Once inhabited by mammoths, mastadons, giant ground sloths, short-faced bears, saber-tooth cats and even lions, the landscapes of America looked much more like that of Africa. This was not as far back as the dinosaurs, yet far enough that evidence is hard to find. Many such places can be found in the arid deserts of the Southwest. Caves full of preserved skeletons and dung provide the evidence needed to reveal the long forgotten past. Having grown up in this region of the world, I enjoyed reading about the wildlife that once roamed this land. Martin gives a well researched position as to why these animals only exist as skeletons in dark caves and dung heaps. Overkill, resulting from the introduction of man, is his reasoning and not the theory of climate change which some believe. However, with radiocarbon dating methods and more and more site discoveries, Martin and his colleagues are able to connect the arrival of man with the disappearance of the extinct megafauna. Overall the telling of this history was excellently laid out. Not to many slow or dry spots, even the part about sampling feces of giant sloths had some excitement to it.
This entire review has been hidden because of spoilers.
184 reviews3 followers
September 14, 2021
A benchmark text in defending a theory against criticism. Martin convincingly goes through all his detractors points against pleistocene overkill and validly dismisses them.

A excellent discussion on the ethics of conservation, the preservation of nature, what makes something "wild", what makes something native or invasive.

I finished ready to start importing elephants and camels.

What I have learned about Quaternary life convinces me that although our desire for conservation and wilderness restoration is admirable, and our efforts have been noble, our present goals are historically shortsighted and far too tame. We are obsessively focused on protecting what we have and utterly unaware of what we have lost and therefore what we might restore. No American terrestrial habitat, from sea to shining sea, has been “natural” for some 10,000 years. Fought-over wilderness areas such as the Arctic National Wildlife Refuge, though vital habitat for remaining megafauna, are already depleted of other large species. Indeed, the only truly pristine faunal wilderness left in the world are the pinniped haulouts and penguin rookeries in Antarctica.
391 reviews
March 12, 2019
A very well-reasoned and exhaustive (to a layman such as I am) treatment on the mass extinctions of most of the large (> 100 kg) animals (mammoths, mastodons, camelids, bovids, carnivores, etc.) in the recent past. While covering the world-wide events, Martin focuses on North America in particular, where the effects are most visible. Arguing for anthropogenic (human-originated) causes instead of climate-change as the primary reason for the rapid faunal turnover, the author draws from multiple studies and disciplines as well as numerous fossil sites from around the world in making his case. Also of interest, the topics of "rewilding" and "fauna recovery" are covered in some detail, with some surprising insights and proposals, including extending the time of faunal look-back for the rewilding effort beyond the Holocene and into the Quaternary.
Profile Image for Garth.
273 reviews1 follower
October 24, 2017
Heavy on science but there is a rich, underlying conclusion that is weaved around the discovery of 40,000 year old Megatherium (Shasta Ground Sloth) dung found in the Rampart cave in a wall of the Grand Canyon. Dr. Martin puts forth a beautifully concise and elegant argument that Man was the sole reason that many Ice Age mammals went extinct when we came on the scene. Do I accept it? Not completely but I do gravitate closer to this theory than I have many others I have read by equally insightful scientists. A truly enjoyable read.
Profile Image for Niall Cavanagh.
179 reviews
October 24, 2024
I love that Martin centres the book around a take that will never be put into action so it can always be argued for. I agree that we should let big cats and elephants roam the North American wild again - let's shake things up! I also found his arguments very convincing for human-led, rather than climate change related, North American megafauna extinction. The details about giant sloths (Martin's specialty) are fun and educating.
30 reviews
April 15, 2024
This book was super boring to read. Very repetitive. The book seems to be a catalogue of the authors research. The last few chapter are totally irrelevant to the title. Disappointing.
Profile Image for Kevin Koppelmann.
643 reviews1 follower
August 17, 2024
A little dry in spots but overall pretty good. I appreciated the premise of bringing back extinct species that once lived in certain areas to restore the ecosystems in those areas.
Profile Image for Talia Rosen.
43 reviews2 followers
January 11, 2026
A lot more conversations about giant sloth dung than I anticipated
Profile Image for Keith Akers.
Author 9 books92 followers
October 20, 2015
This is an interesting and uneven book. It’s part theory, part memoir, all defending the prehistoric overkill hypothesis: the idea that humans were responsible for the extinction of many species in prehistory, due to overhunting. All those mammoths and mastadons, giant sloths, the dire wolf, several species of horses, an American version of the camel, and more besides — rendered extinct shortly after humans arrived in the Americas.

What’s uneven is the writing part. The writing isn’t really awful, it’s just sort of boring in places, and it’s not clear who his audience is. Sometimes he’s writing for specialists in the field, at other times he’s making his case to anyone who will listen. (I’d prefer the latter, as I’m not an anthropologist or archeologist.) However, a clear plus here, this is the only book really making a convincing argument for the overkill idea.

I am continually surprised that the overkill hypothesis is still considered “controversial,” and that people still buy the “climate change” theory of late Quaternary megafauna extinctions. O. K., maybe climate has something to do with it, as Anthony Barnosky has argued, but the whole array of evidence is just too thorough and too incriminating; without humans, most of these species might have suffered, but would not have gone extinct. A whole array of large mammal species, not just in the Americas but in Australia and everywhere, mysteriously vanish just when humans arrive. In the Americas, there’s the complicating factor of climate change, but there are plenty of other places that large mammals went extinct where climate change wasn’t there. To me, the evidence is overwhelming and conclusive. However, given the writing style in this book, I’d say another reason the overkill hypothesis is still “controversial” is Martin’s inability to convey his ideas.

After a chapter on radiocarbon dating, he gives another chapter on the overkill idea. Then we have three chapters on ground sloth dung, ground sloths, and caves in the Grand Canyon. This wasn’t too interesting to me, and is sort of a memoir of his own field research. I would have been quite willing to accept a quick description of the research and his conclusions.

After that, in the chapter “Deadly Syncopation,” he talks about the extraordinary fact that there have been so few large-mammal extinctions, until humans came along, and then suddenly we have a whole bunch. This is not just on the large continents, but on the West Indies, New Zealand, and Madagascar.

In “Digging for the First People in America,” he discusses some sites allegedly showing that humans were here. He discusses, but rejects, the idea that people came to the Americas long before the accepted dating of the last Ice Age — about 13,000 years ago. If humans were in the Americas 20,000 years ago, this throws serious doubt on the overkill hypothesis, since the mammoths didn’t go extinct until the last Ice Age. In “Kill Sites, Sacred Sites,” he discusses some miscellaneous points and objections, including the lack of cave art depicting extinct mammals in the New World (as there is in Europe). In “Models in Collision,” he discusses his debates over the overkill hypothesis versus the climate change hypothesis of extinction.

At the end, in two chapters on “Restoration” and “Resurrection,” he discusses his idea of rewilding America by ditching the use of vast prairies for livestock, but for wild animals instead. It’s interesting that at one point he had to argue with political leaders to allow wild burros and horses to exist in the Southwest. They were not regarded as “native,” but if you really go back 13,000 years ago, animals broadly similar to them were native, but were rendered extinct by human predation.

It’s too bad he’s gone. I’d be interested to see people take his ideas and elaborate on the “Popper thesis” (to abandon much of the prairies to wild animals) in some greater depth. Until someone does this, though, we have this book.
Profile Image for Daniel Morgan.
727 reviews26 followers
July 20, 2020
Let's rip the band-aid off first: a major point not only of this book but of the author's entire career is wrong. Martin pioneered the Overkill Hypothesis, the idea that Clovis culture humans rapidly fanned across the Americas roughly 13000 years ago and caused the extinction of American megafauna through overhunting. Clovis was accepted as the earliest date for the settlement of the Americas for nearly the entire author's life. However, the 21st century brings a nasty, ugly little fact - there are human sites in South America over 20K years old. Thus, humans were apparently living side-by-side with the great meagafauna for thousands of years without causing rapid extinction, which is a massive blow to the argument that the expansion of human settlement was the primary cause of megafauna extinction.

That begin said, I do NOT see that as a mark against the book. With the foreknowledge that this hypothesis will end up being inaccurate, it is really interesting to read how the author constructed his argument. Not only to see what evidence he marshaled in his defense, but also what assumptions and leaps of logic the hypothesis depended on, both consciously and unconsciously. For example, a conscious assumption that Martin made throughout the book is that Overkill obviously depended on human settlement coinciding with megafauna extinction. If human habitation preceded the extinctions (as they did), Martin acknowledged that this would more-or-less invalidate his theory. However, I thought it was interesting that there were a few unconscious assumptions that the author was making. For example, he took the absence of cave paintings as evidence that people were not present - but what if they were destroyed, or not discovered, or if people simply didn't make them to begin with? Or he handwaved the fact that Paleoindian kill sites only contain mammoth and bison remains, which is a major issue in the theory.

Leaving Overkill aside, there are some great standalone parts to this book. For example, the first 70 pages or so are about reconstructing paleoclimate based on ground sloth poop - that's awesome! I really enjoyed looking at the detailed charts of mammalian taxa, the maps of sites, the photographs and diagrams throughout the book - these are so important for bringing the science to life and putting it into context.

Finally, the last few chapters of the book propose a radical idea for conservation, which I think has a lot of merit. The author points out that the stated policy of the National Park Service is to try to preserve the wild lands of America as they were in 1500, before European settlement. The author points out that this is eurocentric - why should the written records of Europeans dictate what America looks like? The modest proposal is that native New World fauna should be allowed to settle in areas where they can survive, even where they did not exist when Europeans arrived. For example, restoring bison, grizzlies, wolves, armadillos, peccaries, jaguars to freely spread throughout the United States. The more radical proposal is that Old World analogues can be settled in America, to fill the ecological niches left empty by their extinct cousins. For example, wild horses and burros replacing the North American equiids, camels and llamas replacing the extinct North American camelids, or elephants serving the ecological role of mammoths. I think that is a fascinating idea.

Beware that Paleoindians vastly predated Clovis, and that a strong Overkill hypothesis has fallen out of favor, to be replaced by climate change as the main driver. That being said, this is neat book, and if you are interested in Cenozoic paleobiology or North American conservationism, you might enjoy this book.
Profile Image for Tina Cipolla.
112 reviews14 followers
August 31, 2015
Fantastic read from the late Paul Martin! If you are interested in environmental issues this book will detail for you the intellectual underpinnings of the rewilding movement.

Keep in mind this book is several years old and some of the information in it is out of date. Nonetheless, I have not seen a better laid out argument for the overkill theory, even though I largely disagree with it. What makes this book so good though, even to one who disagrees with its central argument on near term extinctions is that no better case can be made for rewilding, and no better case can be made as to why people who get their shorts in a knot about "native" species are usually wrong. People who are waging fights, for example, to rid the Americas of "non-native" horses are blithely unaware that prior to human arrival on this continent there were several species of horses native to North America.

Where things get interesting, and where non-environmentalists and people who are against setting aside wilderness areas get really upset, is when this author suggests the reintroduction of some mega fauna and apex predators to the Americas. No, not attempt to clone the extinct American lion, mastodon or woolly mammoth, but he suggests bringing in the living African varieties in these taxa as proxies. Yes, the author is for real, and he got lambasted for this "loopy" suggestion (that term was used by some politicos in reaction to this book.) He makes a compelling case that if ever there is a hope to return the Americas to some of their original pre-human wildness, it can be accomplished by reintroducing proxy species to the Americas that can stand in for their Quaternary counterparts and then just get out of the way and let them evolve.

This is a fascinating read from a really smart guy. This book has been hugely influential in environmental circles and if you are interested in these topics you'll find a lot to think about in these pages.
Profile Image for Adam.
998 reviews241 followers
July 23, 2016
Twilight has the dubious distinction of being one of the only references Mark Shepard cites in Restoration Agriculture. He implies that Martin details some of the Pleistocene ecologies that he urges us to mimic in designing Anthropocene food-producing ecosystems. Such lessons are few and far between in the book, however; Martin lays out the history of the megafauna overkill hypothesis and gives a remarkably fair presentation of the evidence and arguments for and against it, though of course he comes down on the side that made him famous. The end of the book simply hints at the ways Martin's fieldwork in paleontology could inspire unexpectedly productive restoration ecology efforts. Of course, most of these involve importing wild Old World megafauna like camels and llamas, which remains a far cry from Shepard's domestic milieu. So while Shepard is right to point to Martin and Pleistocene ecology as appropriate models for designing new ecosystems, he certainly doesn't do so in any satisfying detail, and Twilight is not a very helpful place to look - though I'm sure the sources Martin cites are probably a good place to start.
Profile Image for Dave Daines.
72 reviews12 followers
January 7, 2009
This was a very interesting quick read (only 216 pg) that my sweet wife got me for Christmas, knowing my fascination for extinct Mammals such as Mammoths, Sabre-tooths, Giant Sloths, etc.

The theory being presented here by the author is that the mass extinctions that occurred among megafauna in the Americas at around 13,000 to 10,000 years ago were caused by overkill from the new Americans, rather than climate change. Other than a couple chapters in which the author goes into great detail about sloth dung and rat middens, it's an interesting read.

It's really a shame when you think about it, that so much animal diversity was killed off by our ancestors of so long ago. Not to put blame on anyone, they were just looking for their next meal. Also interesting how in the case of the first Americans, they sabatoged much of their future by killing off the horse, goats, and other potentially very useful animals before figuring out they were good for more than eating.
Profile Image for P..
65 reviews
May 29, 2008
A good book about the Pleistocene/Holocene interface and the world changed. Interestingly, beyond portraying that world the author wishes to "re-wild" the Americas, restoring the systems that were. The author seems to be firmly on the side of the Pleistocene overkill hypothesis or the climate change model or somewhere in between as to the explanation of the vanished genra of the Americas. That is the most likely explanation.
7 reviews
December 22, 2014
Rewilding of america

Excellent book which strips out political correctness and cultural sensitivity to leave only hard evidence to guide our interpretation of what drove the extinctions of America's megafauna. The ultimate super predator - us. Claiming it was climate change according to the author just doesn't stack up. I'm convinced.
Profile Image for Virginia.
115 reviews
October 16, 2012
This is a very convincing thesis for the human caused extinction of not just the large and varied mammals of North America 11,000 YAG. The pattern of humans moving onto a new continent or island and the extinction of major fauna was repeaded with every expansion. Well worth reading.
Profile Image for Gnomepartay.
117 reviews13 followers
February 26, 2015
Assigned to read this book for an Extinction class in college. For a required text it was rather easy to read and provided interesting insight into how early humans interacted with their environment.
5 reviews
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February 5, 2016
Martin hypothesizes that the earliest Americans literally hunted to death all the animals that lived in North America 11,000 years ago. Fascinating stuff. Very readable book.
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