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Ancient fires drove large mammals extinct, study suggests
- neverrroot 3y agoInteresting, fits the current thing… well?
- cyberax 3y agoMore likely, early humans simply killed off the large herbivores, and the large predators simply starved. This happened in Australia. All the local megafauna disappeared rapidly once humans settled in.
- Blahah 3y agoThe fire hypothesis is compatible with what you said. The idea is that humans either directly or indirectly caused frequent and vast wildfires that destroyed ecosystems, and those fires either killed animals directly or destroyed the resources they needed to survive.
- cyberax 3y agoNot really? Megafauna disappeared everywhere in Americas, including in the Central and South America, that are not susceptible to massive wildfires. It's far more likely that people simply poked animals to death with sharp sticks.
- angiosperm 3y agoIt is completely impossible that people drove all these animals extinct with sharp sticks. People lived in the Americas for thousands of years without affecting them noticeably, and then they all disappeared suddenly, 30+ genera strong, along with the Clovis people. We know from polar ice cores that the Americas were shrouded in dense smoke 12,800 years ago from fires started by the comet strikes at that specific time. Central and South America are certainly susceptible to massive wildfires, like anywhere shrouded with combustibles.
- cyberax 3y ago> It is completely impossible that people drove all these animals extinct with sharp sticks. Why? Spears are extremely effective and deadly. And it happened everywhere else. Megafauna also disappeared in Asia, as soon as humans appeared. > People lived in the Americas for thousands of years without affecting them In other words: animals existed for hundreds of thousands of years, but they disappeared within several hundred of years, right as human settlement waves moved across the Americas.
- angiosperm 3y ago> Spears are extremely effective and deadly. And continents are big, and people very unevenly distributed. 13kya there were few humans on any continent. It takes more than spears to eliminate mastodons, mammoths, short-faced bears, dire wolves, sabretooth cats, cheetahs, camels, horses, giant sloths in one blow. Humans did not drive 30+ genera to extinction in the Americas all in under a century, after coexisting for millennia; and did not lay down a film of dust enriched with platinum over the whole continent, or torch it. They did not wipe out their whole material culture at the same time. Nothing Clovis, or any of those genera, are found anywhere above the layer of platinum-enriched charcoal and ash dust. Horses and elephants did not become extinct in Eurasia, where people hunted far longer. You might notice Africa still sports plenty of megafauna.
- happytiger 3y agohttps://www.hcn.org/articles/wildfire-people-are-starting-a-lot-of-fires-in-the-pacific-northwest https://www.hcn.org/articles/wildfire-people-are-starting-a-... It seems to be a pattern to this day. I view the flames as a kind of Asmovian terraforming.
- gumby 3y agoHow do you think some of those humans hunted in Australia? They would travel to a burnt forest (or set fire to one) and then walk around eating the cooked animals until they'd rotted or been eaten, and then move on.
- candiddevmike 3y agoAnd we still haven't outgrown that behavior. We as a species keep burning the proverbial forests to get an easy win.
- bendbro 3y agoWe are maturing. We will mature. We grow up with heroes these days. Thanks to intrepid companies like Disney who, and despite polluting right wingers best efforts, we have a trove of emotional education material for our next generation. Marvel and Harry Potter are the two greatest inventions of the past 100 years- even more than the mRNA vaccine.
- candiddevmike 3y agoI don't quite follow. Marvel teaches folks to punch their way through problems, and Harry Potter teaches people it's OK to be manipulated by adults because it's your destiny.
- deleted 3y ago[deleted]
- neogodless 3y agoSo kind of interesting, in trying to find a way to view the gist of the content behind the above paywall, I found this article from about 5 years ago: https://www.npr.org/sections/thetwo-way/2018/04/19/604031141/new-study-says-ancient-humans-hunted-big-mammals-to-extinction https://www.npr.org/sections/thetwo-way/2018/04/19/604031141... > New Study Says Ancient Humans Hunted Big Mammals To Extinction > Smith found that when humans arrived someplace, the rate of extinction for big mammals rose
- nemo 3y agoThe NYT article is a theory that considers human behaviors besides hunting: >In a new study published Thursday in the journal Science, a group of paleontologists that analyzed fossil records at La Brea Tar Pits, a famous excavation site in Southern California, concluded that the disappearance of sabertooth cats, dire wolves and other large mammals in this region nearly 13,000 years ago was linked to rising temperatures and increased fire activity spurred by people. This is the article the NYT is citing: https://www.science.org/doi/10.1126/science.abo3594 https://www.science.org/doi/10.1126/science.abo3594
- myshpa 3y agohttps://upload.wikimedia.org/wikipedia/commons/a/ad/Extinctions_Africa_Austrailia_NAmerica_Madagascar.gif https://upload.wikimedia.org/wikipedia/commons/a/ad/Extincti... Humans were the reason, on all continents. https://ourworldindata.org/wild-mammal-decline https://ourworldindata.org/wild-mammal-decline "By around 10,000 years ago we see a huge decline of wild mammals. It’s hard to give a precise estimate of the size of these losses millennia ago, but they were large: likely in the range of 25% to 50%." "It wasn’t just that we lost a lot of mammals. It was almost exclusively the world’s largest mammals that vanished. This big decline of mammals is referred to as the Quaternary Megafauna Extinction (QME). The QME led to the extinction of more than 178 of the world’s large mammals (‘megafauna’)." We lost the biggest animals because those were the ones we hunted. If the reason were to be the fire (which sounds ridiculous), it would have caused the extinction of mammals of all sizes, not just the largest ones.
- ceejayoz 3y ago> Humans were the reason, on all continents. The article doesn't disagree, saying both "increased fire activity spurred by people" and "Dr. Dunn emphasized that this pattern could not account for the notable disappearance of large mammals elsewhere in the world at the end of the last ice age". > If the reason were to be the fire (which sounds ridiculous), it would have caused the extinction of mammals of all sizes, not just the largest ones. No, not necessarily. A small animal can retreat into a burrow an elephant-sized one cannot. They also breed faster afterwards, allowing their populations to recover more readily.
- codexb 3y agoThe mass extinction of large megafauna, all around the world, at roughly the same time, isn't explained by humans (see woolly mammoths). There's far more evidence that it was driven by climate change as the world quickly exited the last glacial maximum.
- myshpa 3y agohttps://edition.cnn.com/2019/10/08/us/woolly-mammoths-death-scn-trnd/index.html https://edition.cnn.com/2019/10/08/us/woolly-mammoths-death-... Last mammoths died 4000 years ago, and they might have even lived longer, if short-term events hadn’t tainted their water and drained their food supply. It wasn't climate change that killed off the mammoths; it was humans. https://www.google.com/search?q=mammoth+house&tbm=isch https://www.google.com/search?q=mammoth+house&tbm=isch We ate them all. It was only when there were no big animals left to hunt that we invented agriculture.
- codexb 3y agoI'd be highly skeptical of this claim. Large megafauna around the entire world began dying off both before and after the last glacial maximum, even in areas where there wasn't a significant human presence. The fact that they died off in North America around that time, too, isn't that surprising. It's also worth noting that at that time, a large part of North America was covered in savanna, which is among the most highly fire-prone habitats, regardless of humans.
- AbrahamParangi 3y agoHold on though, because the correlation between “human arrival” and “megafauna extinction” is extremely high. The timeline of megafaunal extinctions goes: Africa, then Eurasia, then Australia, then North America, and finally South America. No points for guessing the order that humans colonized those continents. In the few historical examples of human introduction to a new ecosystem (New Zealand and Madagascar) within a few hundred years of arrival we’d eaten every animal bigger than a cat.
- londons_explore 3y agoGroups of humans bigger than 10 can, with planning, catch pretty much any wild animal, even without equipment. Simply digging a hole and tricking the animal into it is one approach. Obviously the large animals that have a lot of meat (and might knock down your house) are an obvious target to catch.
- angiosperm 3y agoIsland extinctions are a distinct phenomenon. People never managed to drive anything in Eurasia extinct. Even African and Indian elephants still exist. The North American extinction pulse clearly matches the platinum-dust spike from the comet strike.
- AbrahamParangi 3y agoWhat about the woolly mammoth, steppe mammoth, straight-tusked elephant, European hippopotamuses, aurochs, steppe bison, cave lion, cave bear, cave hyena, Homotherium, Irish elk, giant polar bears, woolly rhinoceros, Merck's rhinoceros, narrow-nosed rhinoceros, and Elasmotherium to name a few?
- pmayrgundter 3y agoSeems that Younger Dryas Impact Hypothesis might fit these observations too. "We obtained radiocarbon dates on 172 specimens from seven extinct and one extant species... spanning 15.6 to 10.0 thousand calendar years before present (ka)." YDIH event is estimated at 12900 BP and includes vast wildfires in its scenario, including in North America. Contrast that with the idea that humans have been in Sapiens form for 200kya+, using fire for longer even than we have been Sapiens and have probably been in the Americas far before 13kya. Is the idea that despite the capability, we only at this specific time started the extinction program? At just the moment when there's sign of a globally catastrophic impact? YDIH seems more parsimonious, yet the paper doesn't mention it. https://en.wikipedia.org/wiki/Talk:Younger_Dryas_impact_hypothesis https://en.wikipedia.org/wiki/Talk:Younger_Dryas_impact_hypo...
- pmayrgundter 3y agoA little more reading.. "All extinct mammals dated in this study have last occurrence dates older than 13.00 ka, with a modeled extirpation time estimate across all taxa of 13.07 to 12.89 ka [using the Gaussian-Resampled Inverse-Weighted McInerney (GRIMW) extinction estimator" Even tighter bound than my comment and still a tight fit around 12900. Figure 1 in their paper shows this as well. In other news, there was recently a "comprehensive refutation" of YDIH (pre-print) that a fave of my, Martin Sweatman, takes a good look at. A lot of this debate comes down to careful dating, error bars, etc. https://martinsweatman.blogspot.com/2023/08/debunking-holliday-et-als-comprehensive.html https://martinsweatman.blogspot.com/2023/08/debunking-hollid...
- erulabs 3y agoWhat’s more intriguing to me beyond the YDIH is that clearly something wild happened during the Younger Dryas period, impact or not. Regardless of what caused the dramatic fluctuations in temperature, wildfires, ocean levels (floods) and megafauna, the fluctuations did occur, and mark the beginning of human civilization as we know it, even though we also know Homo Sapiens existed long before this period. To imagine a period potentially as short as 100 years where the world went from unbearably cold at its warmest to the perpetual summer world we live in now and mega predators simply vanished… if I lived through that period I’d also tell my children to amass resources urgently (and tell stories of the hell world we came from). Who knows how long this insanely human friendly world might last! The idea that our species oldest stories might be about catastrophic climate change is absolutely humbling.
- paganel 3y ago[flagged]
- gamblor956 3y agoBoth things can be true: that ancient fires drove large mammals extinct, and that sea level rise cause a specific local species to go extinct when its habitat was fully flooded.
- paganel 3y agoSo why doesn't the Western media still push the discourse of sea-level rise and "NYC is going to get drowned any minute now!"?
- ceejayoz 3y agoMaybe you're just not reading any of it? Ten days old: https://www.washingtonpost.com/climate-environment/interactive/2023/new-orleans-sea-level-hurricane-wetlands/ https://www.washingtonpost.com/climate-environment/interacti... NYC, specifically: https://abcnews.go.com/Awards/rising-sea-levels-affect-new-york-city-americas/story?id=99583149 https://abcnews.go.com/Awards/rising-sea-levels-affect-new-y...
- rralian 3y agoI don’t understand your point. It seems to be that Western media is somehow biased, but I’m not sure in what way. I’m pretty confident that global temperatures will continue to rise and that sea levels will rise and cause massive problems for coastal populations over my lifetime. But I’m mostly consuming Western media. Do you disagree with these points? And what non-Western media do you feel is more correct?
- ygjb 3y agoBecause rising sea levels doesn't get clicks anymore, but if you read actual literature on the topic, there are ongoing concerns and considerations. On a more practical level, it's not a major North American or European city, so it doesn't capture Western media's attention, but the Republic of Kiribati[1] has an estimated <80 years before it's primary land masses are completely submerged, with some being lost nearly 20 years ago. Kiribati is a canary in a coal mine for climate change related activity in coastal regions. The government of that nation has very progressively purchased land in Fiji, and presumably in other places to aid with resettlement efforts. There have been legal tests (and denials of claims) for at least one person claiming to be a climate refugee from Kiribati. Even before the sea levels rise, the arable land and liveable areas will be wiped out. This isn't theoretical, it just isn't directly affecting (yet) the exceedingly wealthy, major western cities, or white folks, so it doesn't get as much press. Some other areas that are starting to recognize the impacts of rising sea levels include Kolkata, Guangzhou, Miami, New York, and more directly personally affecting me, Vancouver! Unfortunately the main point of recognition is that significant portions of these cities will be below sea level at some point in the next century, barring solutions like seawalls, and other methods to try to save them. It's been almost 20 years since the levees failed in NOLA, but it hasn't stopped people thinking we can hold back the ocean. Things are going to be crazy in the next couple of decades. [1] https://en.wikipedia.org/wiki/Kiribati https://en.wikipedia.org/wiki/Kiribati
- neonate 3y agohttp://web.archive.org/web/20230817201616/https://www.nytimes.com/2023/08/17/science/climate-paleontology-mammals.html http://web.archive.org/web/20230817201616/https://www.nytime... https://archive.ph/cEWop https://archive.ph/cEWop
- AndrewKemendo 3y agoThis is great new information helping to further the debate about causes of the Quaternary Megafauna Extinction (QME). I’ll reiterate here my theory that the specific period following this extinction event, was catastrophic for human civilization and drove humanity to invent property and thus the system of capital and exchange. [0] https://en.m.wikipedia.org/wiki/Quaternary_extinction_event https://en.m.wikipedia.org/wiki/Quaternary_extinction_event [1] https://kemendo.com/Myth-of-Scarcity.html https://kemendo.com/Myth-of-Scarcity.html
- nologic01 3y agoThere is a certain myth that pre-industial peoples were in a more balanced relationship with nature. While less powerful technologies and thus more direct dependence on natural processes and cycles made people more atuned to nature, the broad pattern seems to be one of unhindered consumption (deforestation, hunting etc) the impact of which was limited only by the relatively small population size.
- jacquesm 3y agoAnd by the lack of our present day very powerful tools. https://en.wikipedia.org/wiki/Harvester_(forestry) https://en.wikipedia.org/wiki/Harvester_(forestry) That sort of thing can level a whole forest in a very small fraction of the time it took to grow.
- deleted 3y ago[deleted]
- goatlover 3y agoThe Avatar and noble savage myth. Also used to blame all the ills of modern society on colonialism (and thus capitalism). If only we could go back to living like the indigenous lived!. Well, evidence doesn't favor them being any more noble.
- titzer 3y agoWe used to be limited by what our stomachs could carry, but every leap in technology amounted to storing up more food and resources for later, or consuming them conspicuously for social status, particularly to attract mates. So nowadays not even a few lifetimes of wealth (tens of millions of dollars) is enough to sate.
- MrGuts 3y agoDude, I wake up, turn on the radio, and feel like an extinct megafauna every morning. I'm sure my skull will end up in a closet at the office and taken out every now and again to confer on an old codebase.
- deleted 3y ago[deleted]
- pluc 3y agohas anyone done a study on whether total annihilation of most organic life by fire is bad for us? which profit-oriented megacorporation is currently saying they will save us? does Elon know about this?
- Zamicol 3y agoHorses are native to North America and became extinct after the introduction of humans. https://en.wikipedia.org/wiki/Evolution_of_the_horse https://en.wikipedia.org/wiki/Evolution_of_the_horse >Fossil evidence indicates that mastodons probably disappeared from North America about 10,500 years ago as part of the Quaternary extinction event of most of the Pleistocene megafauna that is widely believed to have been a result of human hunting pressure. The latest Paleo-Indians entered the Americas and expanded to relatively large numbers 13,000 years ago, and their hunting may have caused a gradual attrition of the mastodon population. From https://en.wikipedia.org/wiki/Mastodon#Extinction https://en.wikipedia.org/wiki/Mastodon#Extinction As far as megafauna and climate, see also https://en.wikipedia.org/wiki/Revival_of_the_woolly_mammoth https://en.wikipedia.org/wiki/Revival_of_the_woolly_mammoth
- photochemsyn 3y agoIf you read the study itself, it claims that it's still hard to say what the relative roles of ice age climate change cycles vs. human predation were on the extinction of large Paleocene mammals in North & South America (and Australia): > "Despite decades of research on extinction causality, the relative importance of late-Quaternary climate changes and spreading human impacts have been difficult to disentangle because poor chronological resolution in the fossil record has precluded alignment of these rapidly occurring, tightly linked phenomena." However, it seems pretty clear that wherever humans showed up into new habitats where humans and large animals didn't have a shared ecological-evolutionary history (i.e. not Africa or Eurasia) extinction rates among the megafauna shot way up: https://ourworldindata.org/quaternary-megafauna-extinction https://ourworldindata.org/quaternary-megafauna-extinction > "Africa was the least hard-hit, losing only 21% of its megafauna. Humans evolved in Africa, and hominins had already interacted with mammals for a long time. The same is also likely to be true across Eurasia, where 35% of megafauna were lost. But Australia, North America, and South America were particularly hard-hit; very soon after humans arrived, most large mammals were gone. Australia lost 88%; North America lost 83%; and South America, 72%." Maybe large animal populations had shrank due to the spread of glaciers during the Last Glacial Maximum era (c. 25 kya) so they were more vulnerable, but the new factor (relative to the past 2.5 million years of ice age cycles) was the human predation.
- jojobas 3y ago"Fire-stick farming" (i.e. burning forests to make hunting easier) is said to have helped Aboriginal Australians sort out their megafauna.
- marcus_holmes 3y agoAustralian forests evolved to burn every few years. Any megafauna living in Australia would know how to survive a forest fire (as modern fauna in Australia does), because they'd experience them regularly.
- genter 3y agoA fire burns out the brush, making it easier to see what you are hunting, and easier to chase after it.
- jojobas 3y ago>Australian forests evolved to burn every few years. Except that seems to have happened after they started burning them. >Any megafauna living in Australia would know how to survive a forest fire (as modern fauna in Australia does), because they'd experience them regularly. As per above, not really. Also as many animals worldwide experienced, surviving a bush fire is not as hard as surviving a bald ape with a pointed stick. https://theconversation.com/how-aboriginal-burning-changed-australias-climate-4454 https://theconversation.com/how-aboriginal-burning-changed-a...
- FrustratedMonky 3y agoThe next set of wild fires will eliminate the current dominant mega fauna. The common HOMO-Extreme-BMIans. Or in the vernacular, Large Human Corporate Drone. Typically feeding on vast quantities of cheese-wiz over bacon fries, their combined fat mass contains the combustible energy of the worlds combined nuclear stockpiles.
- deleted 3y ago[deleted]
- dimmke 3y agoSometimes I go down these Wikipedia rabbit holes, and one of the most fascinating to me is extinct animals that were not dinosaurs. Specifically, how a lot of mammal apex predators are similar to extinct versions, just like, half the size. Like the American Lion and Direwolf. Also how this was relatively recent, as others have pointed out they think that a lot of these species went extinct around 10,000 years ago. That fits even conservative estimates of when humans had migrated to the Americas. This is an aside, but I found it really fascinating. Alligators and crocodiles are kind of obviously in the same area from an evolutionary standpoint (they're both in the Order Crocodilia), and they're both thought to be incredibly old - 30 million+ years. But there are only 2 species of Alligator left in the entire world. There's the American alligator which is fairly plentiful all around the Southeast United States and a slightly smaller critically endangered variant in China. There's 18 species of Crocodile, and they're in all the Americas, Australia, New Zealand, all of Asia and a huge portion of Africa. And then I learned about Caimans which I didn't even know existed before. It really goes to show how some branches can be so much more wildly successful than others.
- Tagbert 3y agoThere have been recent evidence that seems to push that 10,000 year entry of humans into the Americas out by as much as another 10K further back.
- bumby 3y agoPossibly 23k years ago https://www.usgs.gov/programs/climate-research-and-development-program/news/discovery-ancient-human-footprints-white https://www.usgs.gov/programs/climate-research-and-developme...
- dimmke 3y agoYes… but there’s so many factors at play that I don’t know enough to speculate with any hope at accuracy about (but will because it’s interesting.) These were modern humans so they had sapience and tools and some form of organization, but how widespread were they vs. the so called “megafauna” - we are talking about A LOT of species with very different biologies here that went extinct. And the timescale isn’t long enough so we know the smaller versions of some of these creatures existed at the same time. Plus, was the hunting for food or defense? If primarily for food, how was the meat preserved? Its easier to imagine a group of humans with spears taking down a lone Direwolf than a pack of giant creatures. It’s hard to reckon with humans being the primary factor in the demise of these creatures when there are still things like grizzly bears out there. I’m sure they didn’t help and in very select situations were the primary cause (such as when a very small isolated species was stuck on an island) but I just don’t know if I buy them being the primary cause of a large scale extinction of a type of organism. The earliest estimates for large scale civilizations like the Mayans were around 7000 BC. It’s hard to imagine humans having such a widespread and profound effect without that level of organization. But I’m a complete amateur on this subject, so this speculation is basically just what I find plausible with some cursory research. Clearly this is a hotly debated topic amongst scientists.
- andreygrehov 3y agoThey were probably releasing too much CO2 into the atmosphere /s
- earthboundkid 3y agoIt’s a living.
- jmyeet 3y agoThe dynamics of evolution are really interesting. As an aside, we like to say we can't predict what life would be like on an alien world as we only have one data point but honestly, I really do wonder if there isn't some universality in the patterns that have evolved here. But I digress. Becoming bigger seems to a strategy driven largely by herbivores as a defense mechanism against predators. Predators seem to get bigger as a response. At least on land. At sea, it seems to work a little differently (eg we have whales that are the largest animals ever to live on Earth that live on very small animals). But being large seems to be a fundamentally risky proposition that sooner rather than later leads to extinction. It just seems harder to adapt. If your food source gets disrupted, it's basically game over. IIRC I read something recently where the megalodon was theorized to have been driven to extinction by the emergence of the (smaller) great white shark that basically stole it's food source (combined with scarcity for other reasons). Then again, dinosaurs were around for 150 million years so what does that say? Was the Earth just relatively stable for that period? Still, dinosaurs died out while birds lived on (and thrived). The end of the last Ice Age killed off a bunch of our larger animals too (eg the wolly mammoth; yes I know it survived in isolation for some time later).