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Ancient fires drove large mammals extinct, study suggests

nytimes.com

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Re: Ancient fires drove large mammals extinct, study suggests

#101

Post by dimmke »

sigil wrote: post #92
dimmke wrote: post #77

Sometimes 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. Th…

You might enjoy the In Our Time episode on Crocodile Evolution. https://open.spotify.com/episode/2v7Dil3bVNiir5BDXxGnTe?si=o... There were crocs with beaks, crocs with plant-grinding molars, crocs that ran around upright on land (yikes). During Earth’s colder periods their range narrows to equatorial regions, and it expands northward & southward during warmer periods. They may rule again someday!

This was incredible. It blew my mind. Thank you so much. I had no idea that crocs were basically the other side of dinosaurs.

Re: Ancient fires drove large mammals extinct, study suggests

#102

Post by jojobas »

marcus_holmes wrote: post #81
jojobas wrote: post #73

"Fire-stick farming" (i.e. burning forests to make hunting easier) is said to have helped Aboriginal Australians sort out their megafauna.

Australian 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.

>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-a...

Re: Ancient fires drove large mammals extinct, study suggests

#103

Post by LargoLasskhyfv »

erulabs wrote: post #41
pmayrgundter wrote: post #28

Earlier quoted context omitted.

A 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 re…

What’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…

https://en.wikipedia.org/wiki/Asterix_and_the_Falling_Sky

Edit: Hrrmph.That was not exactly what I remembered. What I do remember are several references to "The Sky is falling!" in the preceeding comics. Which I later found to be actual reference to some Gauls saying that to Roman elites, when asked about their greatest fear. As written down in some classical latin texts, which I don't remember right now.

Re: Ancient fires drove large mammals extinct, study suggests

#105

Post by Grubbo »

myshpa wrote: post #8

https://upload.wikimedia.org/wikipedia/commons/a/ad/Extincti... Humans were the reason, on all continents. 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 e…

Doesn't explain the ones frozen in place still in the process of chewing grass.

Re: Ancient fires drove large mammals extinct, study suggests

#106

Post by londons_explore »

AbrahamParangi wrote: post #71
codexb wrote: post #9

I'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 hig…

Hold 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…

Groups 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.

Re: Ancient fires drove large mammals extinct, study suggests

#107

Post by londons_explore »

m0llusk wrote: post #89
codexb wrote: post #9

I'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 hig…

There have also been large finds with many dead megafauna together. It is not expected that humans at that time had the ability to slaughter very large numbers of megafauna all together.

If humans find a technique to catch a mammoth (eg. lure it into a big hole), then they will eat mammoth meat... But next week, when the uneaten mammoth meat has gone bad, they will catch another.

After a few years, you have a massive mammoth graveyard and mammoths are extinct. Doesn't seem at all surprising.

Re: Ancient fires drove large mammals extinct, study suggests

#108

Post by sigmaprimus »

ramraj07 wrote: post #95
pmayrgundter wrote: post #10

Seems 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 200…

Humans could have lived nicely in harmony for hundreds of thousands of years in times of abundance, and when sudden cataclysms caused great famines or suffering they could have resorted to more drastic measures that caused large scale fires. Doesn’t mean this is what I think happened, but sounds just as plausible as comets causing havoc to me. In the end IMO this field has been greatly disserviced by Hancock. The yDI…

I agree with most of this. I would say Graham Hancock has some crazy ideas, but the Younger Dryas isn't crazy and his impact on the theory is minimal. If anything the fact that Joe Rogan had him and Randal Carlson as guests on JRE at the same time probably had more impact.

My current thoughts are that the true history of human civilization does go much further back than current narratives and "Experts" claim. Our current civilization has progressed and innovated so much in such a short amount time, it is not unreasonable to expect that humans have built and lost similar civilizations through catastrophes such as the YDB.

It may not have been aliens but I think it is probable that right around the time we started going into space, ancient human made satellites were discovered and brought back to earth. It could also be that Area 51 and other places were created not for Alien space craft crashes but ancient human satellites that were intentionally crashed.

I can only imagine how alien a TESLA found in space by the next civilization might seem!

Considering the way our government leaders and wealthy have historically conducted themselves, it's not hard to believe if they survived a cataclysm, they would be quite willing to be thought of as gods and horde any knowledge they have to themselves.

Fun subject to ponder in anycase!

Re: Ancient fires drove large mammals extinct, study suggests

#109

Post by Reason077 »

myshpa wrote: post #8

https://upload.wikimedia.org/wikipedia/commons/a/ad/Extincti... Humans were the reason, on all continents. 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 e…

> "Humans were the reason, on all continents."

Except the numbers don't really stack up. 10-15k years ago the entire global population of humans was, at best, a few million. And a single megafauna kill would produce enough meat to feed an entire community for weeks. Humans would have had to have been extremely bloodthirsty and systematic in their slaughter, and must have been wasting enormous quantities of meat.

Also, the regions where some megafauna species survive into modern times (ie: Africa and South Asia) were where most of the humans lived. Wouldn't we expect those species to have gone extinct too?

It's certainly possible that humans helped finish off megafauna populations that were already scattered, distressed, and in decline. But it's unlikely that we were the primary or only cause.

> "We lost the biggest animals because those were the ones we hunted."

There's plenty of evidence that ancient humans hunted animals of all sizes. Why would we only go after megafauna as they became rarer and rarer? Instead of smaller species that were far more numerous and accessible?

Re: Ancient fires drove large mammals extinct, study suggests

#110

Post by BizarreOne »

mjan22640 wrote: post #104
urduntupu wrote: post #53

Earlier quoted context omitted.

[flagged]

We actually should unite globaly. The existence of countries is a historic relict that is only causing troubles.

We actually should divide, city-states is where it's at. The existence of countries is a historic relict that is only causing troubles.
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