[HN Gopher] Clues to disappearance of North America's large mamm...
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Clues to disappearance of North America's large mammals 50k years
ago
Author : wglb
Score : 45 points
Date : 2024-06-07 19:56 UTC (3 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| aeonik wrote:
| The new methods being used are cool and all, but I didn't see any
| hints about the extinction explicitly mentioned.
|
| From what I read, it seems that this new bone collagen
| spectroscopy, _may_ , yield insights.
|
| And I'm sure it will, but they weren't in the article from what I
| could see.
| AlbertCory wrote:
| Clickbait. You didn't see them because they weren't there.
|
| The new techniques may identify genus, but no one's used them
| yet to get the dates of extinction.
| soneca wrote:
| Did I understood correctly that we now have tools that will
| likely provide more clues to the disappearance but the text
| mentions no particular clue, yet? (I read it diagonally trying to
| dodge the ads)
| robotbikes wrote:
| That was my read. They can now identify species of very
| fragmentary bone remains via collagen protein matching. They
| didn't say what if anything clues this would/could lead to.
| xhkkffbf wrote:
| My problem with the notion that humans caused the extinction of
| large mammals is that humans supposedly originated in Africa and
| large mammals weren't extinct there. So how did that happen?
| soneca wrote:
| Maybe more abundance of vegetal food during the Ice Age on
| Africa?
| llm_trw wrote:
| The large animals evolved along side humans and learned to
| fear/kill us on sight. All the other mega fauna had to deal
| with fully modern humans who already knew how to hunt.
| chrisco255 wrote:
| I just don't buy that. It's too hand wavey. Natural instinct
| is to fear the unknown, and to respond quickly to threats.
| Saber tooth cats roamed the continent too and there is plenty
| of evidence they hunted humans, along with bears that
| continue to hunt humans to this day. But there were also dire
| wolves, giant bison, cave bears, and many other large species
| that went extinct but for which we have smaller forms of
| alive today. Something must have occurred environmentally
| that led to the rapid deaths of large species.
|
| It's also not as if we have evidence of large populations of
| humans in the glacial era. You would need a modern
| civilization with at least metallic tools to spread far
| enough and wide enough to kill off multiple major species.
| paulryanrogers wrote:
| Humans are surprising resourceful, especially when survival
| is on the line. Even before the metal ages it seems we were
| apex predators.
| benced wrote:
| Larger creatures have long gestation cycles and tend to be
| very sensitive to any any changes. Even killing a few
| pregnant females a year could have been enough in a given
| region.
| baseballdork wrote:
| > It's too hand wavey. Natural instinct is to fear the
| unknown, and to respond quickly to threats.
|
| Doesn't the dodo show that that isn't a given?
| llm_trw wrote:
| They fear the unknown because humans ate all the ones that
| didn't.
|
| During the age of sail whenever a ship would land on a new
| island they local animals could be plucked like fruit
| because they didn't fear humans.
|
| The results were always quite predictable.
| otabdeveloper4 wrote:
| Maybe humans didn't originate in Africa. There are many
| arguments for and against.
|
| But this is an ideological and political issue, not a
| scientific question. So case closed, the Consensus Is Settled.
| thaumasiotes wrote:
| > Maybe humans didn't originate in Africa. There are many
| arguments for and against.
|
| Sure, but the arguments against are in the same vein as the
| argument that, if I draw a circle, it's not a _real_ circle,
| because I don 't have the level of fine control over my hand
| that would be necessary to produce one of those, and the tip
| of my pen is too wide.
|
| True, but not really relevant to anything, and in particular
| unlikely to convince anyone that it's a mistake to call what
| I drew "a circle".
| AlbertCory wrote:
| I have not seen the arguments against. What are they?
| adolph wrote:
| My impression is that relatively recent genetic findings
| open "recent out-of-Africa" to conjectures of "its
| complicated mostly-out-of-Africa"
|
| https://www.edge.org/conversation/christopher_stringer-
| rethi...
| bee_rider wrote:
| Africa is the pro league of evolution. Humans escaped and it
| was like a professional playing in beer league. Unsporting.
| foxandmouse wrote:
| Sorry, but this is clearly a False Dilemma fallocy.
| ftkftk wrote:
| When I go fossiling in Florida almost every large find is from
| the Pleistocene or Holocene, when Florida was not covered by the
| ocean. Identifying the bone fragments is always a big puzzle that
| involves a good bit of study and reference books. A fun puzzle
| for sure, but sometimes you end up with a find that you just
| can't place. It would be great to have a technique such as ZooMS
| to positively identify the unidentifiable.
| throwawaycities wrote:
| Interesting. South, central, north Florida or the coasts? Any
| chance you're looking at coral rock?
| jmclnx wrote:
| I still believe it was due to Humans. Megafauna disappeared
| around the time Humans reached the Americas, way too much of a
| coincidence to me. These mammals were there before the Ice Age
| and I think the coming of the ice age was just as hard on then as
| the retreating ice.
|
| The difference were humans.
| chrisco255 wrote:
| Actually they're not really clear on the timelines of
| extinction and arrival so it's not an open and shut case.
| mdavidn wrote:
| The same fate befell the moa, a large flightless bird native to
| New Zealand.
| lostlogin wrote:
| The Haast Eagle too. They hunted Moa, and as you'd expect
| from an eagle that hunted 200kg birds, it too was a monster.
|
| https://en.m.wikipedia.org/wiki/Haast%27s_eagle
| dexwiz wrote:
| What about the inverse? Humans expanded to the Americas after
| megafauna populations were reduced. Its easy to look at things
| like poaching and assume humans have always been the dominate
| species. But megafanua like moose or brown bears are still
| dangerous, even today.
| cjbgkagh wrote:
| We don't spend much time dealing with mega fauna like moose
| or brown bears anymore so are generally unprepared for it.
| But if it was a bigger part of our lives I'm pretty sure we
| would dominate even with cavemen level tools.
| benced wrote:
| At this point, I regard most efforts in this direction as silly
| and ill-fated attempts to exonerate us. I'm not entirely sure
| why either.
| longitudinal93 wrote:
| It's the same story in Australia. Several large slow creatures
| that disappeared shortly after the arrival of humans. I think
| trying to pin the blame solely on the weather is simply because
| it's much more in sync with the "stewards and custodians of the
| land" narrative that is currently so fashionable.
| sudofail wrote:
| Or simply because we don't have evidance of Homo Sapiens in
| the Americas until ~20k years ago, 30k years after megafuana
| extinction.
| colechristensen wrote:
| There were wooly mammoths alive in 2000 BC, 600 years after
| the Great Pyramid was built. There is evidence of humans
| and mammoths being in north America together.
|
| https://www.livescience.com/woolly-mammoths-in-north-
| america...
| askvictor wrote:
| I thought it was accepted that Australian megafauna went
| extinct due to humans. But could also be a combination of
| factors e.g weakened by a climatic shift then finished off by
| newly arrived human predators
| MaxHoppersGhost wrote:
| My thoughts as well. If the native Americans had the
| technological ability to extinct the Buffalo they would have
| done it. Just as they killed off many more fragile species
| and other tribes. Life in pre Colombian America was just as
| nasty as it was in post Colombian America.
| earthboundkid wrote:
| > If the native Americans had the technological ability to
| extinct the Buffalo
|
| I think it's more the case of if they didn't have the
| ability to create a balance. Things like the creation of
| the Amazon rainforest and the domestication of corn,
| potatoes, tomatoes, quinoa, llamas, etc. were because
| Native Americans figured out how to do those things. It's
| likely though that the first Native Americans just didn't
| know that stuff yet and accidentally ate all the mammoths
| or whatever because they didn't yet have a tradition of
| "only eat the mammoths when the third moon rises after
| Orion returns" or whatever. Those kinds of cultural
| traditions are social technologies, and they enable ways of
| life that would otherwise collapse in a few decades.
|
| In the Pacific, Hawaiians and others had seemingly useless
| taboos like "women can't eat bananas" but following the
| taboo rules sustained a huge population (estimates for
| Hawaii vary, but it was at least a significant fraction of
| the current population without international shipping!).
|
| In the Amazon, manioc is a great staple crop... as long as
| you serve it exactly right so you don't slowly poison
| yourself. They figured that out, but I'm sure there were
| many generations that got it wrong before they got it
| right.
|
| So I don't think the framing should be "plains Indians
| didn't know how to kill off the buffalo." Rather a) plains
| Indians didn't have horses pre-European contact, so that
| whole way of life didn't exist until modernity and b)
| balancing with nature is a learned cultural achievement.
| colechristensen wrote:
| No, it's not about any woo woo natural balance. Mammoths
| were really easy to kill and if they were anything like
| their elephant cousins would have taken 10-15 years to
| reach sexual maturity. Their population would also be
| considerably lower and larger animals are more sensitive
| to change because they reproduce slower and their are
| fewer of them.
|
| Buffalo on the other hand reach sexual maturity at 2-3
| years, there were many more of them. They replaced their
| populations faster.
|
| The first humans in North America didn't extinct buffalo
| because they couldn't, they would have had to have much
| more population and civilization progress before that
| became a risk.
| warcher wrote:
| I have yet to come to a satisfying explanation for the origin
| of that fetish.
|
| I suppose in the absence of any historical record you can
| make up whatever story you like, but the self flagellation
| that comes with it is so weird.
| tazu wrote:
| Isn't is just the noble savage fallacy as usual?
| rfwhyte wrote:
| Another fact that supports this perspective is that the North
| American megafauna survived through numerous cycles of ice ages
| prior to the arrival of humans. There was nothing particularly
| unique or special about the last ice age, the only real
| difference was the presence of humans.
|
| One thing I find particular interesting though, is that there
| are likely two unique extinction events. One around 50KYA, that
| coincides with what I personally believe was the first peopling
| of the Americas, and another around 16KYA, which coincides with
| the arrival of North Americas current indigenous population.
| DarkSucker wrote:
| It seems to me this data could be used to correlate a
| species/genus to a location if one knows where the samples came
| from. If one also knows the date of the geological strata the
| samples came from, then one also has a date correlation. A
| particular animal at a site at some time seems like information a
| researcher can use.
| Efisio wrote:
| EFF
| throwawaycities wrote:
| In case anyone else was wondering, giant beavers didn't construct
| dams.
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