6 ms·

What Happened to the Megafauna?

tomgaga 8y ago
I don't buy this. If the article explains it correctly, the argument is that they can show that in place where the climate was stable, and humans were new, the megafouna went extinct. But that implies that they believe that there were places on the planet were the climate was stable. If you look at the greenland Ice core data, you can see extreme peaks and falls around the last quarterly extinction. So sounds like BS to me.
- civilian 8y ago
  Well then, let's try "relatively stable" rather than "stable". These are scientists who probably have some idea of how to measure variance. You're some rando on the internet shooting from the hip. ¯\_(ツ)_/¯ Here's the paper, go wild: https://www.jstor.org/stable/43601643 https://www.jstor.org/stable/43601643
  - genericone 8y ago
    I think you are being downvoted because you are using the appeal to authority: 'trust them, they have credentials that say they should be trusted on this very subject'. This repurposed quote from the raiders of the lost ark might also work: "I assure you ... We have top men working on it!" "Who?" "Top. Men."
    - civilian 8y ago
      Yeah, I was thinking it was that or my probably-unneccessary flippant attitude. (And btw, I truly do appreciate HN's habit of trying to explain downvotes.) I just get triggered at low-effort skepticism. Tomsaga read the word "stable" and assumed it meant "absolutely stable", and didn't ask himself "huh, I wonder if the pop-sci article is masking a more complicated concept with an easy-to-digest concept". To get more into the climate stability: What they're doing is measuring the difference in temperature and precipitation between the Last Glacial Max and the Last Interglacial. And the maps don't even have `0` in their range, they have a small number but not zero. So yes, climate wasn't stable, but they were able to measure "how stable" it was. (Pages 1-3 in the paper.)
    - cnasc 8y ago
      I think an appeal to authority is only fallacious when it's an appeal to an authority that has no relevant expertise. Something like "my dentist says that anthropogenic climate change isn't real, you don't think you're smarter than a doctor do you?" In contrast, when it comes down to John Q. Internet vs a scientist with relevant expertise, I think it's a reasonable heuristic to think the scientist is more likely to be correct. IMO the downvotes were more related to the delivery than the content.
      - Kaivo 8y ago
        Interestingly, there seems to be an equality bias[1] where the experts opinions weight no more than any other person's opinion. So apparently the reasonable heuristic isn't always applied in how we perceive and judge information. [1]http://www.pnas.org/content/112/12/3835 http://www.pnas.org/content/112/12/3835
      - mythrwy 8y ago
        Yes, but appeal to authority is still appeal to authority as opposed to discussing the merits of the idea. In this place we are better than that. Or we should be. If the discussion was "who is more likely to be right", well, that's a different matter and I'd agree with credentials. But that's not an interesting discussion really.
- tim333 8y ago
  If you look at the 800,000 year data there's nothing that odd to suddenly wipe out megafauna when man arrived https://en.wikipedia.org/wiki/Global_temperature_record#/media/File:EPICA_temperature_plot.svg https://en.wikipedia.org/wiki/Global_temperature_record#/med...
sunstone 8y ago
Perhaps the komodo dragon was the only megafauna to turn the tables on the new humans.
- flukus 8y ago
  I suspect they just taste bad.
  - vanderZwan 8y ago
    IIRC, their hunting method consists of having saliva that is so infested with pathological bacteria that they simply bit their prey and wait for it to succumb to fevers. Somehow, I doubt eating their meat is a healthy thing to do, even when cooked. EDIT: turns out that the BBC documentary I got that from has outdated information: > Although previous studies proposed that Komodo dragon saliva contains a variety of highly septic bacteria that would help to bring down prey, research in 2013 suggested that the bacteria in the mouths of Komodo dragons are ordinary and similar to those found in other carnivores. https://en.wikipedia.org/wiki/Komodo_dragon#Saliva https://en.wikipedia.org/wiki/Komodo_dragon#Saliva
    - sunstone 8y ago
      On the other hand komodo dragons actively hunt humans which is pretty impolite. I would expect that bad habit would lead to their extinction on a small island but it hasn't.
stupidcar 8y ago
Imagine if, instead of spending your childhood, teenage years and early adulthood in schools, you just spent it learning to hunt, then continued to learn and practice hunting for the rest of your life. Imagine if everyone in your family, and everyone else you knew had also spent their entire lives learning to hunt and hunting. Imagine if every genius born into every generation devoted their entire intelligence to the problem of hunting, from their first moment to their last. Imagine if this had been going on for generation after generation, with knowledge and expertise refine and passed down through mentorship and oral tradition. Collectively, it's a level of intellectual effort that humanity has likely never brought to bear on any other problem besides, perhaps, farming. As such, it's perhaps no surprise that early humans were spectacularly successful at hunting so many of even the largest and most fearsome animals to extinction.
- DarkTree 8y ago
  That's a crazy thought. It's also a crazy thought to extrapolate that process all the way to how current first world countries operate. You can kind of start to bridge the gap between the two and see that our society is just an extreme manifestation of that whole scenario you described. We know that in fact there was a direct set of events that got us here, but it's also easy to separate the way humans lived and how we live now, as if they are detached but you can see a lot of those early behaviors still operating in our industrialized society.
- hutzlibu 8y ago
  It is a good thought, but I would like to add, that even in pure hunters societys, you also had different professions. You need to process and store the meat and fur, make the tools, heal wounds, help with births, praise and sacrifice to the gods and spirits (lets assume they do, most if not all native tribes do so), think about neighbour tribes, inner rivals, mating ... so I am basically just nitpicking that not EVERY intellectual capacity avaiable did go to hunting ..
- jessriedel 8y ago
  > Collectively, it's a level of intellectual effort that humanity has likely never brought to bear on any other problem besides, perhaps, farming. I mean, if you are measuring in terms of brain cycles, perhaps. But huge amounts of these brain cycles were wasted because people lived in small tribes and information decayed quickly in space and time, requiring everyone to continually re-invent things. And the detailed knowledge for hunting one type of animal in one region was not particularly applicable to other animals in other regions, so these are to a large extent just different problems.
woodandsteel 8y ago
Interesting, but it raises the question of why the global extinction didn't happen before. Was there a sudden improvement in human hunting techniques? Or did they stay the same, but the added factor of climate change made it possible for the two of them together to do it, or what?
- autokad 8y ago
  the last ice age peaked about 21k years ago and ended about 11.5k years ago. Humans have been around for about 200k years, so it probably took some time 'getting on its feet' and reaching critical mass with the ending of the ice age to cause a global impact. i myself do think we played a larger role. Woolly mammoths actually survived till about 4000 years ago by being in the most remote islands possible. To me, its like something you would see if there was some sort of zombie apocalypse and the last humans only survived in some remote island, far far away from land. Eventually, humans did reach that island, to which the mammoth immediately died off. Though climate change probably played a role, and could have been the primary one, I don't feel it was.
acidburnNSA 8y ago
"Mammals went extinct as humans expanded, and they went extinct in areas where the climate was stable but humans were new." That squares with something I think I read in Guns, Germs, and, Steel, which was that the reason African megafauna like elephants, lions, etc. survived to this day is that they co-evolved alongside humans to the point that they knew to be afraid of the puny little buggers. Meanwhile a 2-ton giant marsupial in Australia had no reason to fear and evade the new bipedal neighbors, or so it thought...
- tim333 8y ago
  There were also a lot of 'germs' in Africa that kept human numbers in check until very recently.
Taniwha 8y ago
TLDR: we ate them
- tim333 8y ago
  Or got annoyed with them. Modern elephants, lions and tigers tend to get problems if they do in crops or villagers.
- burfog 8y ago
  Or we ate their food source. Giant tigers and bears need giant herbivores to eat.
- microwavecamera 8y ago
  Is it our faults they were slow and delicious?
beloch 8y ago
When we go to a museum and see skeletons or life-size models of Pleistocene megafauna, we tend to assume these animals behaved just like the wild animals of today: wary, elusive, and ferocious if cornered. Then we consider the size-difference and shudder. However, extinct megafauna may have behaved differently. The wild animals of today are the product of tens of thousands of years of intense selection pressure from humans. It's possible that a Mammoth behaved less like an African elephant and more like a Dodo. i.e. Humans migrating into areas where humans were previously unknown may have encountered animals that didn't view them as threats and which did not evade pursuit or defend themselves as modern wild game does.
deleted 8y ago
[deleted]
m0llusk 8y ago
We ate them. Now we are the megafauna. Will we eat ourselves?
- bryanlarsen 8y ago
  And cattle: https://xkcd.com/1338/ https://xkcd.com/1338/
- kridsdale1 8y ago
  Zombies are terrifying for a reason. It’s our strengths turned against us. They never stop pursuing.

I don't buy this. If the article explains it correctly, the argument is that they can show that in place where the climate was stable, and humans were new, the megafouna went extinct. But that implies that they believe that there were places on the planet were the climate was stable. If you look at the greenland Ice core data, you can see extreme peaks and falls around the last quarterly extinction. So sounds like BS to me.

civilian 8y ago
Well then, let's try "relatively stable" rather than "stable". These are scientists who probably have some idea of how to measure variance. You're some rando on the internet shooting from the hip. ¯\_(ツ)_/¯ Here's the paper, go wild: https://www.jstor.org/stable/43601643 https://www.jstor.org/stable/43601643
- genericone 8y ago
  I think you are being downvoted because you are using the appeal to authority: 'trust them, they have credentials that say they should be trusted on this very subject'. This repurposed quote from the raiders of the lost ark might also work: "I assure you ... We have top men working on it!" "Who?" "Top. Men."
  - civilian 8y ago
    Yeah, I was thinking it was that or my probably-unneccessary flippant attitude. (And btw, I truly do appreciate HN's habit of trying to explain downvotes.) I just get triggered at low-effort skepticism. Tomsaga read the word "stable" and assumed it meant "absolutely stable", and didn't ask himself "huh, I wonder if the pop-sci article is masking a more complicated concept with an easy-to-digest concept". To get more into the climate stability: What they're doing is measuring the difference in temperature and precipitation between the Last Glacial Max and the Last Interglacial. And the maps don't even have `0` in their range, they have a small number but not zero. So yes, climate wasn't stable, but they were able to measure "how stable" it was. (Pages 1-3 in the paper.)
  - cnasc 8y ago
    I think an appeal to authority is only fallacious when it's an appeal to an authority that has no relevant expertise. Something like "my dentist says that anthropogenic climate change isn't real, you don't think you're smarter than a doctor do you?" In contrast, when it comes down to John Q. Internet vs a scientist with relevant expertise, I think it's a reasonable heuristic to think the scientist is more likely to be correct. IMO the downvotes were more related to the delivery than the content.
    - Kaivo 8y ago
      Interestingly, there seems to be an equality bias[1] where the experts opinions weight no more than any other person's opinion. So apparently the reasonable heuristic isn't always applied in how we perceive and judge information. [1]http://www.pnas.org/content/112/12/3835 http://www.pnas.org/content/112/12/3835
    - mythrwy 8y ago
      Yes, but appeal to authority is still appeal to authority as opposed to discussing the merits of the idea. In this place we are better than that. Or we should be. If the discussion was "who is more likely to be right", well, that's a different matter and I'd agree with credentials. But that's not an interesting discussion really.
tim333 8y ago
If you look at the 800,000 year data there's nothing that odd to suddenly wipe out megafauna when man arrived https://en.wikipedia.org/wiki/Global_temperature_record#/media/File:EPICA_temperature_plot.svg https://en.wikipedia.org/wiki/Global_temperature_record#/med...

sunstone 8y ago

Perhaps the komodo dragon was the only megafauna to turn the tables on the new humans.

flukus 8y ago
I suspect they just taste bad.
- vanderZwan 8y ago
  IIRC, their hunting method consists of having saliva that is so infested with pathological bacteria that they simply bit their prey and wait for it to succumb to fevers. Somehow, I doubt eating their meat is a healthy thing to do, even when cooked. EDIT: turns out that the BBC documentary I got that from has outdated information: > Although previous studies proposed that Komodo dragon saliva contains a variety of highly septic bacteria that would help to bring down prey, research in 2013 suggested that the bacteria in the mouths of Komodo dragons are ordinary and similar to those found in other carnivores. https://en.wikipedia.org/wiki/Komodo_dragon#Saliva https://en.wikipedia.org/wiki/Komodo_dragon#Saliva
  - sunstone 8y ago
    On the other hand komodo dragons actively hunt humans which is pretty impolite. I would expect that bad habit would lead to their extinction on a small island but it hasn't.

stupidcar 8y ago

Imagine if, instead of spending your childhood, teenage years and early adulthood in schools, you just spent it learning to hunt, then continued to learn and practice hunting for the rest of your life. Imagine if everyone in your family, and everyone else you knew had also spent their entire lives learning to hunt and hunting. Imagine if every genius born into every generation devoted their entire intelligence to the problem of hunting, from their first moment to their last. Imagine if this had been going on for generation after generation, with knowledge and expertise refine and passed down through mentorship and oral tradition. Collectively, it's a level of intellectual effort that humanity has likely never brought to bear on any other problem besides, perhaps, farming. As such, it's perhaps no surprise that early humans were spectacularly successful at hunting so many of even the largest and most fearsome animals to extinction.

DarkTree 8y ago
That's a crazy thought. It's also a crazy thought to extrapolate that process all the way to how current first world countries operate. You can kind of start to bridge the gap between the two and see that our society is just an extreme manifestation of that whole scenario you described. We know that in fact there was a direct set of events that got us here, but it's also easy to separate the way humans lived and how we live now, as if they are detached but you can see a lot of those early behaviors still operating in our industrialized society.
hutzlibu 8y ago
It is a good thought, but I would like to add, that even in pure hunters societys, you also had different professions. You need to process and store the meat and fur, make the tools, heal wounds, help with births, praise and sacrifice to the gods and spirits (lets assume they do, most if not all native tribes do so), think about neighbour tribes, inner rivals, mating ... so I am basically just nitpicking that not EVERY intellectual capacity avaiable did go to hunting ..
jessriedel 8y ago
> Collectively, it's a level of intellectual effort that humanity has likely never brought to bear on any other problem besides, perhaps, farming. I mean, if you are measuring in terms of brain cycles, perhaps. But huge amounts of these brain cycles were wasted because people lived in small tribes and information decayed quickly in space and time, requiring everyone to continually re-invent things. And the detailed knowledge for hunting one type of animal in one region was not particularly applicable to other animals in other regions, so these are to a large extent just different problems.

woodandsteel 8y ago

Interesting, but it raises the question of why the global extinction didn't happen before. Was there a sudden improvement in human hunting techniques? Or did they stay the same, but the added factor of climate change made it possible for the two of them together to do it, or what?

autokad 8y ago
the last ice age peaked about 21k years ago and ended about 11.5k years ago. Humans have been around for about 200k years, so it probably took some time 'getting on its feet' and reaching critical mass with the ending of the ice age to cause a global impact. i myself do think we played a larger role. Woolly mammoths actually survived till about 4000 years ago by being in the most remote islands possible. To me, its like something you would see if there was some sort of zombie apocalypse and the last humans only survived in some remote island, far far away from land. Eventually, humans did reach that island, to which the mammoth immediately died off. Though climate change probably played a role, and could have been the primary one, I don't feel it was.

acidburnNSA 8y ago

"Mammals went extinct as humans expanded, and they went extinct in areas where the climate was stable but humans were new." That squares with something I think I read in Guns, Germs, and, Steel, which was that the reason African megafauna like elephants, lions, etc. survived to this day is that they co-evolved alongside humans to the point that they knew to be afraid of the puny little buggers. Meanwhile a 2-ton giant marsupial in Australia had no reason to fear and evade the new bipedal neighbors, or so it thought...

tim333 8y ago
There were also a lot of 'germs' in Africa that kept human numbers in check until very recently.

Taniwha 8y ago

TLDR: we ate them

tim333 8y ago
Or got annoyed with them. Modern elephants, lions and tigers tend to get problems if they do in crops or villagers.
burfog 8y ago
Or we ate their food source. Giant tigers and bears need giant herbivores to eat.
microwavecamera 8y ago
Is it our faults they were slow and delicious?

beloch 8y ago

When we go to a museum and see skeletons or life-size models of Pleistocene megafauna, we tend to assume these animals behaved just like the wild animals of today: wary, elusive, and ferocious if cornered. Then we consider the size-difference and shudder. However, extinct megafauna may have behaved differently. The wild animals of today are the product of tens of thousands of years of intense selection pressure from humans. It's possible that a Mammoth behaved less like an African elephant and more like a Dodo. i.e. Humans migrating into areas where humans were previously unknown may have encountered animals that didn't view them as threats and which did not evade pursuit or defend themselves as modern wild game does.

deleted 8y ago

[deleted]

m0llusk 8y ago

We ate them. Now we are the megafauna. Will we eat ourselves?

bryanlarsen 8y ago
And cattle: https://xkcd.com/1338/ https://xkcd.com/1338/
kridsdale1 8y ago
Zombies are terrifying for a reason. It’s our strengths turned against us. They never stop pursuing.