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What Happened on Easter Island
December 10, 2013 7:42 AM   Subscribe

What Happened on Easter Island - A New (Even Scarier)Scenario A new theory exploring the rise and fall of the people of Easter Island.
posted by agregoli (52 comments total) 26 users marked this as a favorite

 
Conclusion: People can't remember what their great-grandparents saw, ate and loved about the world. They only know what they know. To prevent an ecological crisis, we must become alarmed. That's when we'll act. The new Easter Island story suggests that humans may never hit the alarm...As MacKinnon puts it: "If you're waiting for an ecological crisis to persuade human beings to change their troubled relationship with nature — you could be waiting a long, long time."
posted by justsomebodythatyouusedtoknow at 7:47 AM on December 10, 2013 [6 favorites]


Well at least it wasn't gophers again! I don't agree that the situation described in the piece is scarier, but it does seem plausible.
posted by Mister_A at 7:48 AM on December 10, 2013 [1 favorite]


The issue then, according to this version of the story, is about invasive species. First the rats, which ate all the tree seedlings, and then the hypothesized European STDs, which killed most of the humans. Which kind of means that it wasn't the people's fault, except for letting rats on their canoes, and letting Europeans on the island.
posted by goethean at 7:52 AM on December 10, 2013


Those sea-going canoes were a pretty good size and would have had a lot of food stowed on them, but it's still hard to see how breeding rats would have "stowed away" on them on the original voyage(s) to Easter Island if the travelers didn't want them along. But presumably, they had rats on the islands they came from and were eating them there. Maybe the original migrants to Easter Island intentionally brought rats along as livestock to eat at their destination.

Which kind of means that it wasn't the people's fault
You need to add people to that list of invasive species. But really, every species was invasive at some point during the history of any ecosystem.
posted by beagle at 7:55 AM on December 10, 2013 [3 favorites]


The piece quote a review from the WSJ:

In laboratory settings, Polynesian rat populations can double in 47 days. Throw a breeding pair into an island with no predators and abundant food and arithmetic suggests the result ... If the animals multiplied as they did in Hawaii, the authors calculate, [Easter Island] would quickly have housed between two and three million. Among the favorite food sources of R. exulans are tree seeds and tree sprouts. Humans surely cleared some of the forest, but the real damage would have come from the rats that prevented new growth.


Hawaii was not deforested, although there were apparently a lot of rats. Why or how did rats play a significant role in deforesting Easter Island when they could not or did not in Hawaii?
posted by rtha at 7:56 AM on December 10, 2013 [1 favorite]


Isn't Hawaii significantly bigger? My guess is there are predators on Hawaii that keep the rats in check.
posted by Dr Dracator at 8:03 AM on December 10, 2013


Seems like the rat theory, and its plausibility, can be decoupled from the conclusion about generational memory. I thought the piece was worth reading just for the latter.
posted by sandettie light vessel automatic at 8:10 AM on December 10, 2013 [1 favorite]


Easter Islanders also practiced cannibalism. Maybe violence and cannibalism, as well as disease, caused or exacerbated their population decline
posted by knoyers at 8:11 AM on December 10, 2013 [1 favorite]


There were no land mammals on the Hawaiian islands before people arrived. There were (are) birds of prey, but even they can't keep up with a population that grows as quickly as a rat population does. I'm not suggesting that rats had no role in fucking up the ecosystem of Easter Island, but the implication (which may be more nuanced in the book itself) that they are primarily responsible for the deforestation seems off to me.
posted by rtha at 8:11 AM on December 10, 2013


There is a hypothesis that rats were effective seed dispersers in Hawai'i.
posted by Dodecadermaldenticles at 8:13 AM on December 10, 2013


Why or how did rats play a significant role in deforesting Easter Island when they could not or did not in Hawaii?

Jared Diamond wants to know that too. Here's his response to the rat theory (hint: he doesn't like it).
posted by beagle at 8:13 AM on December 10, 2013 [4 favorites]


Isn't Hawaii significantly bigger? My guess is there are predators on Hawaii that keep the rats in check.

Not really. In fact, Hawaiian plantation owners imported mongooses to hunt the rats. Of course, mongoose are active primarily during the day while rats are nocturnal, so the mongooses mostly went after native birds instead. They're now about as common as squirrels are in North America.

Hawaii is long overdue to import mountain gorillas to take care of their mongoose problem. Then the gorillas will freeze to death in the harsh Hawaiian winter and the ecosystem will return to its natural state.
posted by justsomebodythatyouusedtoknow at 8:22 AM on December 10, 2013 [8 favorites]


But I like Tang.
posted by Shepherd at 8:28 AM on December 10, 2013 [11 favorites]


Conclusion: People can't remember what their great-grandparents saw, ate and loved about the world. They only know what they know. To prevent an ecological crisis, we must become alarmed. That's when we'll act. The new Easter Island story suggests that humans may never hit the alarm...As MacKinnon puts it: "If you're waiting for an ecological crisis to persuade human beings to change their troubled relationship with nature — you could be waiting a long, long time."

The great thing about this is that it also applies to politics and economics (up to a certain point, or we would never have revolutions). That's why the TSA is never going to go away, it's perfectly normal to everyone under, say, 18. And that's another reason why the creeping police state isn't going away either. And don't expect the wealth gap to close any time soon.

Gosh, I get so cheery in these dark and grey winter months!
posted by entropicamericana at 8:33 AM on December 10, 2013 [15 favorites]


Oh come on. Maybe the Easter Islanders knew perfectly well what the rats were doing to the trees. Presumably they would have done something about it if they could. Maybe they did try to do something about it. But even now, in highly industrialized, wealthy societies, we have trouble eradicating invasive rat populations, and we can do things like drop poisoned bait over a wide area from helicopters. What exactly were the Easter Islanders supposed to do to "change their troubled relationship with nature"? Getting used to it was pretty much their only option -- would he have preferred that they just curl up and die of shame?

On the other hand, in 2013, while humanity as a whole has the ability and the demonstrated willingness to cause a lot more harm than the Easter Islanders did, we also have more tools at our disposal to try to reverse it. Maybe we'll use them, maybe we won't. But Easter Island is just not a very good example to prove that Humanity is Complacent and we're all doomed to accept the metaphorical rat meat.
posted by ostro at 8:34 AM on December 10, 2013 [2 favorites]


grape Tang was not so bad
posted by thelonius at 8:34 AM on December 10, 2013


I used to like Tang. Then they added a bunch of artificial sweeteners. Now it's dreadful. Weird to contemplate that something that artificial could actually be rendered even more artificial.

I can definitely see the complacency hypothesis working. Heck, it works in my own house. I've got piles of stuff in one hallway I've been meaning to take out/discard for years.
posted by kinnakeet at 8:35 AM on December 10, 2013 [3 favorites]


Previously (Easter Island) and Previously (rat islands)
posted by stbalbach at 8:40 AM on December 10, 2013 [1 favorite]


Oh, and if this reporter had done even the extremely cursory Google search I just did, he would have found out that rat eating appears to have been quite common in prehistoric Hawaii, Samoa and New Zealand, among other places, where there were plenty of other options. It wasn't exactly a status food, but it wasn't taboo the way it is now. See pages 491-493.
posted by ostro at 8:50 AM on December 10, 2013


Jared Diamond wants to know that too. Here's his response to the rat theory (hint: he doesn't like it).

Unless he's flat out lying, he makes a pretty compelling case. One claim he makes is that the rat hypothesis has been rejected by virtually all the other archeologists and anthropologists working on Easter Island. Anyone in a position to comment on that?

I must say that in the linked piece the flat assertion that this rat is some kind of super forest-destroying plague is pretty weird, given that it's found on pretty much every island the polynesians ever settled on. We need at least something else in the equation to explain what happened on Easter Island.
posted by yoink at 8:51 AM on December 10, 2013 [2 favorites]


beagle: "Those sea-going canoes were a pretty good size and would have had a lot of food stowed on them, but it's still hard to see how breeding rats would have "stowed away" on them on the original voyage(s) to Easter Island if the travelers didn't want them along. But presumably, they had rats on the islands they came from and were eating them there. Maybe the original migrants to Easter Island intentionally brought rats along as livestock to eat at their destination."

When you think of a rat, I bet you're thinking of brown rats (Rattus rattus) rather than Polynesian rats (Rattus exulans). Exulans are smaller than brown rats, so you'd be less likely to notice them. In addition, describing Polynesian ocean-going vessels as "canoes" is about as apt as describing 747s as "small jets". Their travelling vessels had indoor areas, room for dozens, and areas for cooking food while at sea. These were big boats, and there'd be ample room for rats to hang out.

As far as I'm aware, there have never been rat remains found on Eastern Island in stratigraphic layers below those where we find the first evidence for humans. They came with people, or at least very shortly before people arrived.

As regards most of the rest of Polynesia, and at least for sure the areas from which Easter Island would have been settled, rats weren't really high on the list of things to be eaten. Go figure: when you're living in the tropics with almost limitless (at the time) fishing stocks and near-shore crustaceans -- not to mention all the pigs and chickens roaming your island! -- rats just weren't worth the effort.
posted by barnacles at 8:52 AM on December 10, 2013 [3 favorites]


rtha: "Hawaii was not deforested, although there were apparently a lot of rats. Why or how did rats play a significant role in deforesting Easter Island when they could not or did not in Hawaii?"

Different kinds and numbers of trees!

The Hawaiian islands have a huge diversity of trees, but Easter Island had a pretty depauperate selection of just about everything (floral and faunal). It appears that before humans got there it was covered primarily by one type of tree, the Easter Island Palm. These trees had never had to evolve in the presence of predators like the rats, and while they were probably absolutely perfectly adapted to the conditions of Easter Island, that perfect adaptation didn't allow for any flexibility when the tiny furry predators arrived.
posted by barnacles at 8:56 AM on December 10, 2013 [6 favorites]


beagle: "
Jared Diamond wants to know that too. Here's his response to the rat theory (hint: he doesn't like it).
"

Hunt and Lipo have been banging this drum of theirs for (off the top of my head) probably 7 or 8 years now, and Diamond has never been super keen about it. It always seems like most of his complaints come from a position of simply not understanding the archaeology, and not accepting it. For instance, the whole thing there about Hunt and Lipo rejecting previous radiocarbon dates is partly due to stuff that happened throughout Pacific archaeology since the mid-90s. One laboratory people had been using for dating turned out to have had some pretty questionable results and so basically everything that they did up to a certain point has just been dropped. And then also, we've learned a lot more about how later nuclear tests have messed up radiocarbon dating, particularly in the Pacific where people were nuking atolls with reckless abandon.
posted by barnacles at 9:03 AM on December 10, 2013 [1 favorite]


The Wikipedia entry on Easter Island is kinda hilarious at the moment. There's clearly editing wars afoot over these different theories. Take a look at this wonderfully schizophrenic passage:
The Polynesian rat, which the original settlers brought with them, played a very important role in the disappearance of the Rapanui palm. Although some may believe that rats played a major role in the degradation of the forest, only less than 10% of palm nuts contained teeth marks from rats. The remains of palm stumps in different places indicate that humans caused the trees to fall because in large areas, the stumps were cut efficiently.[49] The clearance of the palms to make the settlements, led to their extinction almost 350 years ago.
posted by yoink at 9:04 AM on December 10, 2013 [5 favorites]


ostro: "Oh, and if this reporter had done even the extremely cursory Google search I just did, he would have found out that rat eating appears to have been quite common in prehistoric Hawaii, Samoa and New Zealand, among other places, where there were plenty of other options. It wasn't exactly a status food, but it wasn't taboo the way it is now. See pages 491-493."

I can't get your link to work (??) but I've got a copy of that paper on my other computer, and I've clearly forgotten the details (heh!). Backing you up, though, here's a link to a PDF with information on rat eating in New Zealand and Niue (PDF). I still can't recall ever reading stuff about rat eating in Samoa like that, though -- and if I weren't supposed to be packing now I'd go see if I can dig more up!
posted by barnacles at 9:08 AM on December 10, 2013


Hunt and Lipo have been banging this drum of theirs for (off the top of my head) probably 7 or 8 years now, and Diamond has never been super keen about it. It always seems like most of his complaints come from a position of simply not understanding the archaeology, and not accepting it.

The question of what Diamond personally feels about their work seems less interesting to me than the question of what archeologists and other relevant specialists who specialize in work on Easter Island make of it. I've found one paper by Andreas Mieth and Hans-Rudolf Bork (pdf) which claims to "refute" the rat hypothesis. But I'd be interested to know if anyone here could summarize the general scholarly consensus on Hunt and Lipo's hypothesis.
posted by yoink at 9:15 AM on December 10, 2013 [1 favorite]


I bet you're thinking of brown rats (Rattus rattus)

I think those are the slightly littler black rats? Brown rats are the norwegian ones. Norvegicus or something.
posted by elizardbits at 9:23 AM on December 10, 2013



Isn't Hawaii significantly bigger? My guess is there are predators on Hawaii that keep the rats in check.

Not really. In fact, Hawaiian plantation owners imported mongooses to hunt the rats


What about Hawaiian centipedes? Surely they munch on the occasional baby rat.
posted by ocschwar at 9:24 AM on December 10, 2013


Jared Diamond kind of sucks, remember?

Not surprised that his Big Important Story That Explains Everything is likely to be wrong about this too.
posted by edheil at 9:26 AM on December 10, 2013


It was definitely the rats...
posted by ennui.bz at 9:29 AM on December 10, 2013


One niggling question: If everybody was eating enough, why did the population decline? Probably, the professors say, from sexually transmitted diseases after Europeans came visiting.

They can't seriously claim that the Rapanui went from having seagoing canoes and a fish based diet to scraping by with wind-trated vegetable gardens, and not suffer a population decline at the time.
posted by ocschwar at 9:33 AM on December 10, 2013


There are other, smaller failed Polynesian island settlements. Completely failed, like evidence folks lived on Pitcairn long before some troublemaking Europeans settled on it. I think Rapa Nui is particularly appealing to us because of the moai, and because Europeans found it so far removed from the rest of the world. It's a shame we don't have more descriptive records between European contact in 1722 and Captain Cook's visit in 1774. It never occurred to me to think about the impact of European STDs in that period.

Tangentially related: the book Vaka Moana, a big accessible book about Polynesian history, with particular attention paid to navigation and population migration. The second chapter from Geoff Irwin is particularly good, talking about the evidence for a deliberate and carefully planned series of exploratory voyages that populated the Pacific. Only tangentially related because the book doesn't have a lot to say about Rapa Nui; even for Polynesia it's quite an outlier. But it does give you a bit more context about how Polynesians managed a trade network over thousands of miles of ocean.
posted by Nelson at 9:39 AM on December 10, 2013 [4 favorites]


Carl Lipo and Terry Hunt tell the story themselves, in far greater detail, in this Seminar on Long Term Thinking
posted by narcotizingdysfunction at 9:44 AM on December 10, 2013


There is some evidence that Neolithic settlers from southern France or northern Spain to Orkney imported voles as food animals, and that paper also mentions Polynesians deliberately taking rats on long voyages to eat.

Fast breeding, easily transported and reasonably omnivorous animals do sound quite useful for this purpose, and it's not as if rodents aren't regularly eaten through choice elsewhere. I have no idea what an Orkney Vole tastes like and I've never found a recipe for one (the closest I've come is a Roman recipe for puffballs stuffed with minced dormouse... mmm...) but protein is protein. Especially on long sea voyages in small boats.
posted by Devonian at 9:49 AM on December 10, 2013 [1 favorite]


Jared Diamond kind of sucks, remember?

I think choosing which hypothesis you will support based on whether or not it is the one preferred by someone you think "kinda sucks" is probably not the best path to the truth. The question of whether or not rats destroyed the Easter island ecosystem is not one that hinges on one's personal opinions about Diamond. He didn't do the research that either side of the debate is drawing on and his larger thesis does not stand or fall depending on who turns out to be right about Easter Island.
posted by yoink at 9:52 AM on December 10, 2013 [10 favorites]


"F*ck Jared Diamond"?

Generally when establishment opinion (right or left) falls to that level, I assume that the object of scorn might be on to something. Especially when the author appears to have a distinct bent. Time to read his books, I suppose.
posted by IndigoJones at 10:11 AM on December 10, 2013 [3 favorites]


harsh Hawaiian winter

Dude there are Canadians here, don't rub it in
posted by Hoopo at 10:47 AM on December 10, 2013 [1 favorite]


Hoopo, I see Vancouver in your profile. I'm sorry to hear that your rainy winter weather is getting you down.
posted by justsomebodythatyouusedtoknow at 11:39 AM on December 10, 2013 [3 favorites]


generational memory. like the monkeys/gorillas - bananas - ladder - cold water story.

if you haven't heard it, it's a decent metaphor for institutional convention, and may have even been loosely based on an actual scientific study. read it for yourself. worth noting: i had a good time poking around for info on this.
posted by rude.boy at 11:45 AM on December 10, 2013


I'm sorry to hear that your rainy winter weather is getting you down

(Grew up in Ottawa, and so far Vancouver winter has been proper cold and dry)
posted by Hoopo at 12:26 PM on December 10, 2013


forgive an old marxist a marxist read -
people learned to live with less and forgot what it was like to have more. Maybe that will happen to us.
It has been happening to "us" for 40 years, only question is when can we start eating rat?
posted by Abinadab at 12:38 PM on December 10, 2013 [2 favorites]


It has been happening to "us" for 40 years, only question is when can we start eating rat?

what time does mcdonald's open?
posted by pyramid termite at 1:11 PM on December 10, 2013 [1 favorite]


but seriously, there's one thing that kind of puzzles me - people object rightly that on other polynesian islands, the rats didn't destroy all the trees

but on other polynesian islands, the polynesians didn't cut down all the trees, either

was it really the statue obsession that caused the trees to go? -at some point, doesn't someone say, hey guys, we're almost out of trees, maybe we should give it a break?

couldn't have climate change had something to do with it? - or perhaps some kind of palm tree infestation that easter island palm trees were vulnerable to?

i'm no expert, but something doesn't quite add up here
posted by pyramid termite at 1:18 PM on December 10, 2013 [1 favorite]


doesn't someone say, hey guys, we're almost out of trees, maybe we should give it a break

I don't have my copy of Collapse handy, but I'm almost positive Diamond says that since the deforestation isn't happening under some central authority, nobody on one side of the island knows that the other side is now empty of trees, so if you cut down all your trees, you don't really realize that you've contributed to the total denuding of the island. You always have in the back of your mind, well, I'm out of trees, but at least the other side of the island has plenty.
posted by mittens at 1:32 PM on December 10, 2013


Or for that matter, even if the rats were preventing natural growth of trees, why the islanders didn't plant any themselves. They apparently managed to keep the rats from eating their crops, or sufficient amounts to stay alive, so presumably they could have kept them off their palm orchards, and palm nuts have a great many uses, including food, other than making boats. It rather suggests that the situation had sufficiently disintegrated that they didn't think there was much chance of them being able to use the palms even in the 5-10 years it takes for them to start producing. And if you have gone from being able to do the sort of long-term organization that it takes to build maoi to so unstable it's not even worth planting an orchard... that's pretty fucking post-apocalyptic. Not really something I would call an "unlikely success."
posted by tavella at 1:35 PM on December 10, 2013


I like the theory that the palms were cut down for the edible palm hearts. The problem with the idea that the palms were cut down for rollers is that this would necessarily be a slow process and it would be obvious that they were losing their trees. If the island experienced a Malthusian crash, though, people would have been eating everything they could get their hands on (including palm nuts) and uprooting young palm trees as well as cutting down mature ones.
posted by Joe in Australia at 1:56 PM on December 10, 2013


at some point, doesn't someone say, hey guys, we're almost out of trees, maybe we should give it a break?

Maybe, but on the other hand, we don't have any shortage of well-attested historical examples of humans exploiting a renewable resource up to and beyond the point of no return--and that even when there's plenty of people saying "stop, you fools, we need to conserve or we're all doomed."
posted by yoink at 2:05 PM on December 10, 2013


Rats can cause significant damage as you can see in this slightly related, but interesting none-the-less NOVA episode Rat Attack. Why do huge swarms of rats overrun a bamboo forest in India once every half-century?

Program Description

Once every 48 years, bamboo forests in parts of northeast India go into exuberant flower. Then, like clockwork, the flowering is invariably followed by a plague of black rats that appear to spring from nowhere to spread destruction and famine in their wake. For the first time on film, NOVA and National Geographic capture this rat population explosion in vivid detail and show how scientists are unraveling the connections between bamboo flowering and rat outbreaks. Ultimately, their research should help local people better cope with the next attack—due in 2056.
posted by lstanley at 2:20 PM on December 10, 2013 [3 favorites]


"If you're waiting for an ecological crisis to persuade human beings to change their troubled relationship with nature — you could be waiting a long, long time."

One of the reasons you'll be waiting is that you don't see yourself as part of nature.
posted by benbenson at 2:51 PM on December 10, 2013 [1 favorite]


"...at some point, doesn't someone say, hey guys, we're almost out of trees, maybe we should give it a break?"

But we still have some trees. Let the next generation figure out what to do when there's none.
posted by Kevin Street at 3:08 PM on December 10, 2013 [2 favorites]


Despite the article's attempt to sway me to the contrary, I still find humanity's ability to muddle through quite comforting and inspiring. We are part of several massive, only partially-understood systems. We should try to not harm those systems, but no attempt will be perfect, humans being human and complex systems being complex systems.

"We'll muddle through" should go on a banner!

Also: Tang? Pure unexamined classism, that bit. I have very fond memories of being served Tang when visiting my grandmother, I'll have you know.
posted by erlking at 3:30 PM on December 10, 2013


I bet you're thinking of brown rats (Rattus rattus)

Rattus Rattus is totally going to be the name of my jazz band.
posted by 4ster at 8:13 PM on December 10, 2013


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