Today, it's undeniable that humanity holds a profound influence over Earth's climate and its biodiversity. However, contrary to modern media sensationalism, this relationship is not a recent revelation but a saga as ancient as time itself. Human impact on our planet's intricate web of life stretches back tens of thousands of years — possibly even since they first sauntered into the picture.<br /><br />Recent <a href="https://www.cambridge.org/core/journals/cambridge-prisms-extinction/article/latequaternary-megafauna-extinctions-patterns-causes-ecological-consequences-and-implications-for-ecosystem-management-in-the-anthropocene/E885D8C5C90424254C1C75A61DE9D087">studies</a> have spotlighted the extinction or rapid decline of large mammals over the past 50,000 years. While <keyword id="19907392" type="General" weightage="20" keywordseo="climate-change" source="keywords">climate change</keyword> was once a convenient scapegoat, it has proven insufficient to explain these phenomena. Instead, mounting evidence implicates human activity as the primary driver.<br /><br />This phenomenon, known as the <keyword id="22261268" type="General" weightage="20" keywordseo="late-Quaternary-megafauna-extinction" source="Orion">late-Quaternary megafauna extinction</keyword>, marks a significant departure from previous extinction events in Earth's history, with distinct characteristics that set it apart. Unlike earlier extinction events that were often localised, the late-Quaternary extinctions were global in scope and severe in impact. They disproportionately affected larger-bodied species, with megaherbivores weighing over 1,000 kg particularly vulnerable. Shockingly, of the 57 known megaherbivore species from this period, only 11 survived beyond 1,000 AD, highlighting the scale of loss.<br /><br /><h2>Tale as old as time<br /></h2>The narrative begins roughly 100,000 years ago, a time when mammoths roamed icy plains, sabre-toothed tigers prowled lush jungles, and giant ground sloths navigated primaeval forests. Despite the formidable odds, <em>Homo sapiens</em>, armed with finely crafted spears, ascended to the top of the food chain. However, their ascent left behind a trail of dwindling populations and silent extinctions.<br /><br />Previous periods of dramatic climate shifts, like ice ages, didn't cause such widespread extinction of large animals. New research highlights key points that point towards human intervention:<br /><br /><ul><li>Timing: Megafauna extinctions coincided with the arrival of modern humans in different regions around the globe.</li><li>Targeted hunting: Evidence from archaeological digs, like traps and spear points, suggests humans actively hunted these large animals. Isotope analysis even reveals that these giants were a major food source for our ancestors.</li><li>Vulnerability of megafauna: Large animals with slow reproduction rates were particularly susceptible to overhunting by humans.</li></ul>Yet, the impact wasn't limited to extinctions. Even species that survived, like elephants, bears, kangaroos, and antelopes, bore lasting scars from humanity's rise. A 2023 study analysing the DNA of 139 surviving megafauna species reveals a troubling decline in their populations over the last 50,000 years.<br /><br />Further, challenging prevailing theories that blame climate change for extinctions, study author Jens-Christian Svenning emphasised that many extinct megafauna inhabited temperate or tropical climates, undermining climate as the sole explanation.<br /><br /><h2>Looking ahead<br /></h2>The loss of so many large animal species has had profound ecological consequences worldwide. These include disruptions to trophic processes, alterations in physical environmental engineering such as landscape modification, and changes in the transport of energy and matter within ecosystems. The repercussions of these extinctions continue to reverberate through modern ecosystems.<br /><br />In response to these ecological shifts, efforts in megafauna-based trophic rewilding have gained traction as a potential strategy for ecosystem restoration under current global change scenarios. By reintroducing large herbivores into landscapes, researchers and conservationists aim to re-establish ecological processes and enhance biodiversity.<br /><br />Furthermore, the interplay between megafauna and human-driven biotic globalisation underscores the complex relationships between species and ecosystems. Domesticated megafauna, such as livestock, present both ecological challenges and opportunities in managing modern landscapes.<br /><br />As debates continue among scholars — whether to blame climate change or human migration — the echoes of history resound clearly. Standing on the brink of a new era where our technological prowess imperils ecosystems and countless species, the story of these giants serves as a stark warning. What remains to be seen is if we heed the lessons from their decline and the enduring impact humanity has etched into the fabric of evolution, or if we will repeat the errors of our ancestors, leaving only silence in our wake?<br />

Over 80% of prehistoric megaherbivores went extinct due to human activity and not climate change: Study

<ul class="summary-list"><li>North America used to be crawling with giant mammals, from dire wolves to big cats.</li><li>Horses and camels evolved on the continent while others, like bison, crossed over from Asia.</li></ul><p>Towering 13 feet tall and weighing a hefty 7 tons, the African elephant is the biggest land mammal on Earth. But that wasn't always the case.</p><p>Tens of millions of years ago, shortly after the dinosaurs went extinct, mammals grew to epic proportions, dwarfing the animals we see today.</p><p>"There used to be cow-sized wombats in Australia, and there were armadillos the size of cars in South America," Emily Lindsey, an assistant curator at the La Brea Tar Pits and Museum, told Insider.</p><p>Some evolved on these continents while others crossed the Bering Land Bridge, which once connected Asia and Alaska.</p><div type="image" title="A map in shades of brown and blue showing the Bering Land Bridge connecting Asia and Alaska." height="650" width="1300" msid="105218368" hostid="261" sizebytes="46194"></div><p>North and South America were home to woolly mammoths, mastodons, giant sloths, and much more.</p><h2>Columbian and woolly mammoths</h2><div type="image" title="People gather around the fossilized skeleton of a woolly mammoth at the QUADRAT museum in Germany" height="1500" width="2250" msid="105218370" hostid="261" sizebytes="275752"></div><p><strong>Height: </strong>12 to 13 <a target="_blank" href="https://ucmp.berkeley.edu/mammal/mesaxonia/elephantidae.php"><u>feet tall</u></a> (Columbian mammoths); 9 to 11 feet tall (woolly mammoths)</p><p><strong>Weight: </strong>10 tons (Columbian mammoths); 4 to 6 tons (woolly mammoths)</p><p><strong>When did they go extinct?</strong> 13,000 to 10,000 <a target="_blank" href="https://www.nps.gov/whsa/learn/nature/mammoth.htm"><u>years ago</u></a> (Columbian mammoths); 4,000 years ago (woolly mammoths)</p><p>Two types of <a target="_blank" href="https://www.businessinsider.com/russia-pleistocene-park-mammoths-2016-3">mammoths</a> roamed North America. Both are members of the proboscidean family, which also includes modern elephants, and stem from a species that evolved in Africa 5 million years ago.</p><p>The Columbian mammoth arrived in North America about 1.5 million years ago, traveling over the <a target="_blank" href="https://www.businessinsider.com/eighteen-thousand-year-old-stone-tools-among-oldest-found-us-2023-9">Bering Strait</a>, which once connected Asia and Alaska. They fanned out at least as far south as Mexico, <a target="_blank" href="https://www.tandfonline.com/doi/abs/10.1080/02724634.1997.10010985"><u>possibly all the way</u></a> to Costa Rica.</p><p>In North America, "you only get the woolly mammoths up in the north, starting around the Great Lakes," Lindsey said. They arrived later, roughly 100,000 years ago, and didn't venture as far south.</p><p>One of the woolly mammoth's most distinctive features is its thick fur. The Columbian mammoth was far less shaggy.</p><h2>American mastodons</h2><div type="image" title="People look at the fossilized skeleton of an American Mastodon at the Natural History Museum" height="1500" width="2250" msid="105218373" hostid="261" sizebytes="309920"></div><p><strong>Height:</strong> 8 to 10 feet tall</p><p><strong>Weight:</strong> 4 to 5 tons</p><p><strong>When did they go extinct?</strong> Around 11,000 years ago</p><p>A tad smaller than their woolly mammoth relatives, American mastodons were also more widely spread. Their fossils <a target="_blank" href="https://www.sdnhm.org/exhibitions/fossil-mysteries/fossil-field-guide-a-z/mastodon/"><u>have been found</u></a> all over the continent, from Alaska to central Mexico.</p><p>Some <a target="_blank" href="https://www.businessinsider.com/r-bachelor-party-finds-rare-mastodon-fossil-in-new-mexico-2014-12"><u>mastodon fossils</u></a> show them living in North America as far back as 16 million years ago. The forest dwellers likely fed on trees and shrubs.</p><p>In addition to their smaller stature, mastodons had shorter, straighter <a target="_blank" href="https://www.businessinsider.com/mammoth-tusk-found-ocean-deep-sea-2021-11">tusks than mammoths</a>. But paleontologists mainly distinguish them by their teeth. <a target="_blank" href="https://www.insider.com/boy-found-ancient-mammoth-tooth-grandmas-backyard-2023-5">Mammoth molars</a> are fairly flat. American mastodons have bumpier molars.</p><h2>Camels</h2><div type="image" title="Camelops and Hemiauchenia are shown next to each other in an artist's rendering" height="1500" width="2568" msid="105218377" hostid="261" sizebytes="71476"></div><p><strong>Height:</strong> <a target="_blank" href="https://www.nps.gov/articles/000/the-camels.htm"><u>7 feet tall</u></a></p><p><strong>Weight:</strong> 1,800 pounds</p><p><strong>When did they go extinct? </strong>10,000 years ago</p><p>"We think of camels as this very exotic creature that we associated with very different places, with sand dunes, but <a target="_blank" href="https://www.businessinsider.com/fossil-discovery-california-ancient-elephants-camels-dogs-2021-5">camels actually are native</a> to North America," Lindsey said.</p><p>Its relatives evolved 44 million years ago during the Eocene period. Over time, Camelops made its way to the Canadian Yukon and Mexico, making its home in woodlands, grasslands, and wetlands.</p><p>The Camelops was about a foot taller than modern camels, but it's difficult to tell from their fossils if they had a hump.</p><p>These animals crossed the Bering land bridge into Asia 7 million years ago and gave rise to modern camels. More recently, they arrived in South America via the Isthmus of Panama, another land bridge that formed between North and South America<strong> </strong>3 million years ago.</p><p>Some of Camelops' ancestors went extinct, Lindsey said. Others continued to evolve. "Those are the llamas and guanacos that you see in South America today," she said.</p><h2>Horses</h2><div type="image" title="Several skeletons of ancient horses are lined up in glass cases at the Field Museum in Chicago" height="1500" width="2175" msid="105218378" hostid="261" sizebytes="281496"></div><p><strong>Height:</strong> <a target="_blank" href="https://www.nps.gov/articles/000/ancient-horse.htm"><u>4.5 feet tall</u></a> (Equus scotti)</p><p><strong>Weight:</strong> 1,100 pounds (Equus scotti)</p><p><strong>When did they go extinct? </strong>About 10,000 years ago</p><p>Over 50 million years ago, horses started evolving in North America. There were many species, all different from today's versions.</p><p>"When they start out, they're very small," Lindsey said, comparable to small dogs. Instead of hooves, they had five toes<strong> </strong>on their feet.</p><p>Then, 15 million years ago, the landscape and climate started changing. It was drier. Grasslands emerged.</p><p>Horses became larger, with longer legs and fewer toes. Some migrated to Eurasia, <a target="_blank" href="https://www.businessinsider.com/ancient-horses-stripes-like-zebras-until-human-domestication-2016-1">becoming zebras</a> and wild Asian horses.</p><p>"Then they get wiped out in the Americas and brought back about 12,000 years later when the Spanish come," Lindsey said.</p><h2>Short-faced bears</h2><div type="image" title="A saber-tooth cat and a short-faced bear roar at each other in an artist's rendering" height="1500" width="2000" msid="105218381" hostid="261" sizebytes="471100"></div><p><strong>Height:</strong> 11 feet tall when standing on their hind legs</p><p><strong>Weight:</strong> 1,500 to 2,200 pounds</p><p><strong>When did they go extinct? </strong>Between 12,7000 and 11,000 years ago</p><p>Hundreds of thousands of years ago, the Arctodus simus cast a looming shadow over boreal forests, plains, tundra, grasslands, and subtropical woodlands. Known as the short-faced bear, it ranged across the US and Canada, into Florida.</p><p>"The short-faced bears were huge," Lindsey said. They were far larger than 8-foot-tall grizzly bears and "would've been terrifying."</p><p>Studies have shown that its muzzle was perhaps not as short as its name suggests. Some researchers <a target="_blank" href="https://iceage.museum.state.il.us/mammals/short-faced-bear-0"><u>also think</u></a> the bear may have been an omnivore instead of solely a meat eater.</p><h2>Dire wolves</h2><div type="image" title="A reconstuction of a dire wolf with another dire wolf in the background at the La Brea Tar Pits and Museum" height="810" width="1440" msid="105218383" hostid="261" sizebytes="90070"></div><p><strong>Height:</strong> 3 feet tall at the shoulder</p><p><strong>Weight:</strong> 130 to 150 pounds</p><p><strong>When did they go extinct?</strong> An estimated 10,000 years ago</p><p>Dire wolves were big. "But they're not as big as they're shown <a target="_blank" href="https://www.insider.com/game-of-thrones-direwolves-original-plans-meaning-cut-2020-10"><u>in 'Game of Thrones</u></a>,' I'm sorry to say," Lindsey said. She calls them the linebacker version of wolves, about 20% larger than gray wolves.</p><p>Once <a target="_blank" href="https://tarpits.org/stories/our-evolving-understanding-dire-wolves"><u>thought to be</u></a> the cousins of gray wolves, dire wolves evolved separately over 5 million years ago in North America. The finding came courtesy of ancient DNA.</p><p>Lindsey said the news was surprising because they're so similar behaviorally and morphologically. For example, they likely lived in packs like modern dogs, wolves, and coyotes.</p><p>Researchers know quite a bit about how dire wolves hunted, too. "Scientists have looked at <a target="_blank" href="https://www.businessinsider.com/dire-wolf-and-sabre-tooth-cat-bones-show-what-prehistoric-hunts-were-like-2017-5"><u>injuries in dire wolves</u></a>, as well as saber-tooth cats, that were found in the tar pits," Lindsey said.</p><p>They found injuries to the fossils' paws and skulls. "That's consistent with the type of injuries we see in, say, wolves today that are chasing down animals on the landscape," Lindsey said. A wolf's prey might trample its toes or kick it in the head.</p><h2>Saber-tooth cats</h2><div type="image" title="A child crouches under a replica of a saber-tooth cat at the National Museum of Scotland in Edinburgh" height="1500" width="2185" msid="105218387" hostid="261" sizebytes="219738"></div><p><strong>Height:</strong> 3 feet at the shoulder (smilodon and scimitar)</p><p><strong>Weight:</strong> 300 to 500 pounds (scimitar cat); up to 750 pounds (smilodon)</p><p><strong>When did they go extinct? </strong>Roughly 10,000 years ago (smilodon); between 10,000 and 28,000 years ago (scimitar)</p><p>You may have grown up calling them saber-toothed tigers, but the smilodon isn't a close relative of tigers. Their common name comes from their impressive canine teeth, which could be up to 7 inches long.</p><p>Another genus of <a target="_blank" href="https://www.businessinsider.com/dire-wolf-and-sabre-tooth-cat-bones-show-what-prehistoric-hunts-were-like-2017-5">saber-tooth cats</a>, Homotherium, is known as scimitar cats. Their teeth weren't as long as smilodon and were serrated like a steak knife. Like the smilodon, they lived in North America during the Pleistocene. The two cats were similarly widespread, from the Yukon to Florida.</p><p>But these two predators had different prey, according to <a target="_blank" href="https://www.cell.com/current-biology/fulltext/S0960-9822(21)00434-6"><u>a study</u></a> from a few years ago. While the smilodon went after tapirs (pig-like animals with trunks)<strong> </strong>and deer, scimitars preferred baby mammoths.</p><p>"Saber-tooth cats tend to get a lot of injuries in their lower back, which is consistent with this idea that they were ambush predators," Lindsey said. The smilodons would sit and wait before leaping onto a large animal and wrestling it to the ground.</p><p>"It's very easy to torque your back that way," Lindsey said. "And so they get a lot of lower back arthritis type of injuries."</p><p>Lindsey was also part of <a target="_blank" href="https://affiliate.insider.com?h=42246614699244699707dd7c242788d80d4a91432fafa7103792e8fe2d509dd0&amp;postID=654c1e6cb0b368bea7429e8a&amp;postSlug=extinct-giant-mammals-pleistocene-megafauna-ice-age-north-america&amp;site=bi&amp;u=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs41598-021-99853-1"><u>a study</u></a> that diagnosed a smilodon with hip dysplasia based on a CT scan of a fossil. "It's an animal that probably couldn't have survived to adulthood as it did without other animals taking care of it," she said. "So that indicates that these are probably social creatures. There's all kinds of amazing, fun things you can learn from bones."</p><h2>Giant sloths</h2><div type="image" title="Visitors look at a large skeleton of a giant ground sloth in a museum in Florida" height="1500" width="2250" msid="105218389" hostid="261" sizebytes="462358"></div><p><strong>Height:</strong> 19.6 feet when upright</p><p><strong>Weight:</strong> Up to 3 tons</p><p><strong>When did they go extinct? </strong>10,000 years ago or into the Late Holocene</p><p>For most extinct Pleistocene megafauna — animals <a target="_blank" href="https://royalsocietypublishing.org/doi/10.1098/rspb.2019.2643"><u>weighing more</u></a> than 100 pounds — there are still living analogs. Instead of mammoths, there are elephants. Camelops has its camel and llama relatives.</p><p>"But you don't have anything in the world that is even kind of like a 3,000-pound sloth," Lindsey said. "That's just something that is completely gone."</p><p>Unlike their modern counterparts, these behemoths spent most of their time on the ground instead of in trees.</p><p>North America had several species of <a target="_blank" href="https://www.businessinsider.com/giant-sloths-hunted-by-humans-bones-2019-3">giant sloths</a>. Among the largest were the Eremotherium, which have mostly been found in the southeast along Florida and the Gulf Coast, as well as in Central and South America.</p><p>"They like sort of the wetter, more tropical regions," Lindsey said. "They got to be about the size of elephants." While very large, the Eremotherium wasn't as big as the Megatherium <strong>— </strong>another species of giant sloth — which lived throughout South America.</p><p>The <a target="_blank" href="https://www.businessinsider.com/fossils-of-giant-sloth-found-in-sinkhole-2019-3">giant sloths</a> had a diverse diet, including being able to reach higher into the trees thanks to their stature and ability to stand on their hind legs. Exactly when they went extinct is disputed, but their adaptability may have helped them survive a bit longer than many other mammals they lived alongside.</p><h2>American lion</h2><div type="image" title="Three lions crouch drinking from a pond in an artist's rendering" height="480" width="960" msid="105218391" hostid="261" sizebytes="46584"></div><p><strong>Height:</strong> 4 feet at the shoulder</p><p><strong>Weight:</strong> Up to 770 pounds</p><p><strong>When did they go extinct? </strong>Between 10,000 and 12,000 years ago</p><p>Saber-tooths weren't the only big cats that made their home in North America. Panthera atrox was one of the largest<strong> </strong>members of the cat family<strong> </strong>ever.</p><p>"The <a target="_blank" href="https://www.businessinsider.com/ancient-american-lion-fossil-found-in-dried-up-mississippi-river-2022-11">American lions</a> were huge," Lindsey said. "They're much, much bigger than modern lions."</p><p>While fairly rare in the fossil record, there's evidence the big cats did make their way throughout North America. Scientists have found their bones and teeth from Canada to Mexico.</p><p>Researchers <a target="_blank" href="https://phys.org/news/2010-05-scientists-american-lion.html"><u>have debated</u></a> about whether these gigantic cats are more closely related to modern lions or jaguars. Its skull shares similarities with lions', but its jaw resembles those of jaguars and tigers.</p><p>Due to its enormous size, the American lion was able to make meals out of bison and wild horses.</p><h2>Ancient bison</h2><div type="image" title="The mummified skull of an extinct bison behind a glass case at the Smithsonian Institution's National Museum of Natural History" height="1500" width="2218" msid="105218393" hostid="261" sizebytes="191042"></div><p><strong>Height:</strong> 7.5 feet tall</p><p><strong>Weight:</strong> 3,500 pounds</p><p><strong>When did they go extinct? </strong>Roughly 10,000 years ago</p><p>Unlike the Camelops and horses that evolved in North America, other big beasts migrated in. That includes ancient bison.</p><p>"They are the most recent arrivals into North America of all the Pleistocene megafauna," Lindsey said.</p><p>The first bison species appeared around 3 million years ago in South Asia and China. Eventually, some crossed the Bering Land Bridge. They start showing up in the North American fossil record between 300,000 and 130,000 years ago.</p><p>The ancient bison, Bison antiquus, was 25% larger than those living today. Their territories included grasslands, woodlands, and wetlands from Canada to Mexico.</p><p>Another species of bison on the continent was the Bison priscus or steppe bison. A <a target="_blank" href="https://www.sciencedirect.com/science/article/abs/pii/S1040618221002421"><u>recent study</u></a> suggested modern bison — Bison biso — evolved from this species.</p><h2>Why did they go extinct?</h2><p>Was it the changing climate, human interactions, or a combination that caused so many large mammals to go extinct around 10,000 years ago?</p><p>"That is something that scientists have been debating for about 70 years," Lindsey said. The climate was changing at the <a target="_blank" href="https://www.businessinsider.com/what-earth-looks-like-during-an-ice-age-2014-5">end of the Ice Age</a> on a global scale. Humans were also spreading throughout the world.</p><p>"These two things are so closely tied in time, the climate changes and the <a target="_blank" href="https://www.businessinsider.com/eighteen-thousand-year-old-stone-tools-among-oldest-found-us-2023-9">spread of human populations</a>, it's been really hard to say to what degree each of those factors was involved in the extinctions," Lindsey said.</p><p>Humans may have more of an impact than just hunting, too. A 2023 paper tied <a target="_blank" href="https://www.businessinsider.com/fires-may-have-caused-la-brea-tar-pit-extinctions-thousands-of-years-ago-2023-8"><u>fires started by humans</u></a> to some of the extinctions in what is now California.</p><p>If that did have an impact on the animals in that region, the causes might vary for others. "Different ecosystems are going to have different parameters of what pushes them to the brink," Lindsey said. "But there is something about the combination of humans and an unstable climate or a rapidly changing environment that pushes ecosystems again and again towards tipping points."</p>

Dire wolves, camels, and other extinct giant mammals that used to live in North America

<p>A world without humans would look a lot more like an African savanna.</p><p>A new <a href="http://biorxiv.org/content/early/2015/04/01/017368">study</a> found that if homo sapiens had never come into existence and spread across the globe, large mammals like giant sloths and ancient horses would roam the Americas, while elephants and rhinos would dominate Northern Europe, as shown in the map below. (The scale depicts the number of large mammal species that would have existed, where red means more species.)</p><p><div class="KonaFilter image-container display-table"><div><div class="image"><img src="https://static-ssl.businessinsider.com/image/55d740eebd86ef19008b4ef3-800-363/world-without-humans.jpg" alt="world without humans" data-mce-source="Soren Faurby" data-link="http://biorxiv.org/content/early/2015/04/01/017368" /><p class="source"><span><a href="http://biorxiv.org/content/early/2015/04/01/017368">Soren Faurby</a></span></p></div><p></p></div></div></p><p>Instead, here's the disturbing reality of what the world's large animal distribution looks like with humans:</p><p><div class="KonaFilter image-container display-table"><div><div class="image"><img src="https://static-ssl.businessinsider.com/image/55d7527d9dd7cc25008b5075-800-363/world-with-humans.jpg" alt="world with humans" data-mce-source="Soren Faurby" data-link="http://biorxiv.org/content/early/2015/04/01/017368" /><p class="source"><span><a href="http://biorxiv.org/content/early/2015/04/01/017368">Soren Faurby</a></span></p></div><p></p></div></div></p><p>The findings show just how big of a role humans have played in the extinction of megafauna around the world, the researchers say.</p><p>"There used to be a remarkably diverse fauna of large mammals in the New World," study co-author Soren Faurby, an evolutionary biologist at Aarhus University in Denmark, told Business Insider.</p><p>But these animals weren't adapted to dealing with anything as cunning as a human hunter, he said. In a previous study that Faurby led, he and his colleagues found the expansion of humans around the world was responsible for the mass extinction of large mammals during the last ice age (about 130,000 years ago) and the period following it, known as the late-Quaternary megafauna extinction.</p><p>Now, they have taken it a step further, and created a model of how these animals would be distributed if humans had never entered the picture.</p><h2>How they did it</h2><p><div class="KonaFilter image-container display-table float_right"><div><div class="image on-image"><img src="https://static-ssl.businessinsider.com/image/4ef5d7466bb3f70964000017-400-300/steven_strait_in_10,000_b.c._wallpaper_9_800.jpg" alt="caveman" data-mce-source="http://www.10000bcmovie.com/" /><p class="source"><span><a href="http://www.10000bcmovie.com/">www.10000bcmovie.com</a></span></p></div><p></p></div></div>For species that are still alive today, the researchers used historical estimates of animal populations. For extinct species, they estimated the numbers of these animals based on those of other species that were alive at the same time.</p><p>If humans didn't exist, the diversity of animals - especially large mammals - would have been much greater in many parts of the world, the researchers found.</p><p>For example, elephants and their relatives, giant sloths, huge armadillos, horses, and tapirs were once common throughout North America, but most of them disappeared around the time humans first arrived.</p><p>The researchers also looked at how humans impacted the range of things that animals do in their ecosystems. For example, a mouse has a very different role in its environment than an elephant does.</p><p>This range, known as functional diversity, would have been much greater without humans around, but this was true for all land-dwelling animals, not just large mammals (as shown below). The top row shows the functional diversity of large mammals with humans (i) and without us (j); the bottom row shows the diversity of all land animals with (k) and without us (l).<div class="KonaFilter image-container display-table"><div><div class="image"><img src="https://static-ssl.businessinsider.com/image/55d767cbbd86ef13008b5047-1112-391/functional-diversity.png" alt="functional diversity" data-mce-source="Soren Faurby" /><p class="source"><span>Soren Faurby</span></p></div><p></p></div></div></p><p>The landscape might have looked pretty different too. The more large animals you have, the more trees they knock down, resulting in grasslands like the African savanna.</p><p>It's tough to pinpoint the reason for these extinctions. Hunting probably played a big role in the disappearance of herbivores. But many carnivores also went extinct, either because their prey was gone, or because they had to compete with humans for it, Faurby said.</p><p><div class="KonaFilter image-container display-table float_right"><div><div class="image on-image"><img src="https://static-ssl.businessinsider.com/image/55156e04ecad041f40fe0c0d-1024-680/5899473679_bc16b154e1_b.jpg" alt="woolly mammoth" data-mce-source="Flickr/Mammut" /><p class="source"><span>Flickr/Mammut</span></p></div><p></p></div></div>We often think of Africa as being incredibly rich in species diversity. But in fact, parts of Europe and the New World (like Texas and Argentina) were once just as rich, Faurby said.</p><p>In addition, the bigger diversity of animals we see in mountainous areas may be at least partly due to the fact that mountains provided protection from hunting and habitat destruction.</p><p>The findings not only give us a better understanding of global biodiversity, but could also aid in conservation efforts, by establishing baseline levels of many different species.</p><p>The study only looked at how the presence of humans affected the number of different species, not the size of their populations. That's much harder to do, although it's possible to make crude estimates based on an animal's body size, Faurby said.</p><p>The research was based on historical estimates of animal populations, which are sometimes spotty or nonexistent. And estimating the number of extinct animals based on other animals alive at the time is not always accurate, since they may not have existed at exactly the same time.</p><p>Still, the effects of humans on the diversity of animals is probably an underestimate. "Humans are influencing everything to some extent," Faurby said.</p><p> </p>    <div class="margin-top">        <h3>NOW WATCH: <a href="http://www.businessinsider.com/us-earths-ice-melted-animated-map-climate-change-2015-7">Here's what the US would look like if all the Earth's ice melted</a></h3>        <div>            <div>    <script src="http://player.ooyala.com/v3/6e12e8b3387a44daacfb73afba25a76e"></script>    <div class="ooyala-video-player" data-video-autoplay="false" data-video-id="Z4dGwzdDrnZunZUB10-CqEUToYnAvsHw" data-player-variable="ooyalapopvideo" id="ooyalaplayer_popvideo" style="width:1280px;height:720px"></div>    <script>    if (typeof RunFunctions === 'undefined') { var RunFunctions = []; }     RunFunctions.push(function()    {         var ooyalapopvideo = OO.Player.create('ooyalaplayer_popvideo', 'Z4dGwzdDrnZunZUB10-CqEUToYnAvsHw',{ autoplay: 'false' });     });    </script>    <noscript><div>Please enable Javascript to watch this video</div></noscript></div>        </div>        <script>(function() { function createPlayer() { OO.ready(function() { RunFunctions.forEach(function(ooyalaFunction) { ooyalaFunction(); }); RunFunctions = [];}); } createPlayer(); }()); </script>    </div>

Disturbing maps show how mankind has driven some of the world's largest animals into extinction

<ul class="summary-list"><li>Researchers discovered thousands of drawings adorning three rock shelters in the Colombian <keyword id="18635" type="CITY" weightage="60" keywordseo="Amazon">Amazon</keyword>.</li><li>The drawings cover more than 2.5 miles of rock and are at least 11,800 years old.</li><li>They depict an ancient hunter-gatherer society that lived at the end of the Ice Age, with scenes of humans hunting mastodons and images of other extinct animals like Ice Age horses.</li></ul><p>More than 12,000 years ago, near the end of the Ice Age, humans hunted mastodons: ancient mammals that resembled a cross between mammoths and elephants. But by around 11,600 BCE, humans had likely killed many of the mastodons off. </p><p>At least, that's the leading theory among many paleontologists. A recent discovery bolsters it: Researchers recently uncovered thousands of drawings from an Ice Age-era tribe, hidden deep in the Amazon rainforest.</p><p>The drawings are spread across three rocky shelters in Colombia's Serranía La Lindosa region. They were first painted between 12,600 and 11,800 years ago. The largest shelter alone, Cerro Azul, has drawings covering more than 2.5 miles of its surface. The images show some of South America's earliest inhabitants and their interactions with Ice Age-era animals, including giant sloths, ancient llamas, and Ice Age horses.</p><p>Some drawings, like the one below, even depict what experts think are <keyword id="1541215" type="PERSON" weightage="60" keywordseo="Mastodon">mastodon</keyword> hunts.</p><div type="image" title="Mastodon hunt" height="1200" width="1600" msid="79534712" hostid="261"></div><h2>Thousands of ancient, remarkably detailed images </h2><p>Many of the images show unusual levels of detail for such ancient art, according to José Iriarte, a professor of archaeology at Exeter University and a leader of the team that made the discovery.</p><p>"The Ice Age horse had a wild, heavy face," Iriarte <a href="https://www.theguardian.com/science/2020/nov/29/sistine-chapel-of-the-ancients-rock-art-discovered-in-remote-amazon-forest">told The Guardian</a>. "It's so detailed, we can even see the horse hair. It's fascinating."</p><p>The researchers published a study about the three sites in April in the journal <a href="https://www.sciencedirect.com/science/article/abs/pii/S1040618220301907">Quaternary International</a>. But on Monday, the University of Exeter <a href="https://www.exeter.ac.uk/news/research/title_829032_en.html">released a statement</a> with information about the discovery to coincide with the sites' coverage in an episode of "Jungle Mystery: Lost Kingdoms of the Amazon," a documentary series set to air in the UK starting Saturday. </p><p>Mark Robinson, an environmental archaeologist at the University of Exeter and coauthor of the April study, said in a statement that the people who produced these paintings likely moved into South America at a time of "extreme climate change." The Ice Age was ending.</p><div type="image" title="ancient horse.JPG" height="1200" width="1600" msid="79534716" hostid="261"></div><p>"The Amazon was still transforming into the tropical forest we recognise today," he said. "The paintings give a vivid and exciting glimpse in to the lives of these communities. It is unbelievable to us today to think they lived among, and hunted, giant herbivores, some which were the size of a small car." </p><p>The paintings are so vast and numerous that they will likely take many years to study fully. Plus, Jeison Lenis Chaparro-Cárdenas, an anthropologist at the National University of Colombia and member of the research team, told Business Insider that "the vast majority" of cliffs in the region have not yet been fully explored.</p><h2><strong>A deeper look into the lives of prehistoric Amazonians</strong></h2><div type="image" title="pictogram amazon colombia .JPG" height="1200" width="1600" msid="79534718" hostid="261"></div><p>In addition to ancient megafauna, the cliff and cave drawings depict alligators, tapirs, monkeys, turtles, serpents, and porcupines. They also include geometric shapes, as well as everyday scenes showing people hunting and interacting with plants and trees. </p><p>"There are many things and moments of excitement and amazement," Chaparro-Cárdena said. He added that most images revolved around a common theme: "the majesty of the nature that surrounded them and with which they interacted in their daily lives."</p><div type="image" title="ochre tablet" height="505" width="646" msid="79534721" hostid="261"></div><p>The team conducted soil excavations around the rock-art sites to find clues about how the inhabitants scraped clay to extract ochre, a pigment they used to make the drawings. </p><p>Those investigations revealed the remains of animals likely eaten by the ancient people, including piranhas, turtles, armadillos, and capybaras, according to Chaparro-Cárdenas. Modern-day inhabitants of the Amazon rainforest still eat many of the animals found at the sites.</p><p>"This shows a great variety of resources that were used by the inhabitants of the Amazon for more than 12,000 years," Chaparro-Cárdenas said.</p><h2>A perilous journey '100% worth it' </h2><p>The team first began studying the region in 2014, two years before the FARC struck a peace treaty with Colombia's government. The Serranía La Lindosa region falls under FARC territory, and entering safely still requires careful negotiations with the guerilla group, <a href="https://www.theguardian.com/science/2020/nov/29/sistine-chapel-of-the-ancients-rock-art-discovered-in-remote-amazon-forest">according to The Guardian</a>.</p><p>The region also has many natural hazards. Poisonous snakes and caimans inhabit the area, which is an hours-long journey from the nearest town. </p><p>At one point, a large, venomous bushmaster snake blocked the research team's path. They had to walk around it, knowing they were far from any hospital, as the Guardian reported.</p><p>"You're in the middle of nowhere," Ella Al-Shamahi, an archaeologist who worked with the team on the forthcoming documentary, told The Guardian. But she added that braving the dangers was "100%" worth it.</p>

You Searched For "late Quaternary megafauna extinction" and got 4 results

Over 80% of prehistoric megaherbivores went extinct due to human activity and not climate change: Study

Ashmita Gupta

Dire wolves, camels, and other extinct giant mammals that used to live in North America

Jenny McGrath

Disturbing maps show how mankind has driven some of the world's largest animals into extinction

Tanya Lewis

More than 2.5 miles of cliff paintings found hidden in the Amazon rainforest show ancient hunter-gatherers killing Ice Age creatures

Susie Neilson