Woolly mammoth extinction has lessons for modern climate change

Jun 12, 2012
A woolly mammoth skeleton with 90 percent of its original bones on display at the Venetian Resort Hotel Casino in Las Vegas, Nevada, in 2009. Rising temperatures, changing vegetation and the spread of humans all contributed to the extinction of the woolly mammoth, according to a new study that said no single factor was to blame.

Although humans and woolly mammoths co-existed for millennia, the shaggy giants disappeared from the globe between 4,000 and 10,000 years ago, and scientists couldn't explain until recently exactly how the Flinstonian behemoths went extinct.

In a paper published June 12 in the journal Nature Communications, UCLA researchers and colleagues reveal that not long after the last ice age, the last woolly mammoths succumbed to a lethal combination of climate warming, encroaching humans and habitat change — the same threats facing many species today.

"We were interested to know what happened to this species during the climate warming at the end of the last ice age because we were looking for insights into what might happen today due to human-induced climate change," said Glen MacDonald, director of UCLA's Institute of the Environment and Sustainability (IoES). "The answer to why woolly mammoths died off sounds a lot like what we expect with future climate warming."

MacDonald, a professor of geography and of ecology and evolutionary biology, worked with UCLA IoES scientists Robert Wayne and Blaire Van Valkenburgh, UCLA geographer Konstantine Kremenetski, and researchers from UC Santa Cruz, the Russian Academy of Science and the University of Hawaii Manoa.

Their work shows that although hunting by people may have contributed to the demise of woolly mammoths, contact with humans isn't the only reason this furry branch of the Elephantidae family went extinct. By creating the most complete maps to date of all the changes happening thousands of years ago, the researchers showed that the extinction didn't line up with any single change but with the combination of several new pressures on woolly mammoths.

When the last ice age ended about 15,000 years ago, woolly mammoths were on the rise. Warming melted glaciers, but the still-chilly temperatures were downright comfy for such furry animals and kept plant life in just the right balance. It was good weather for growing mammoths' preferred foods, while still too cold for the development of thick forests to block their paths or for marshy peatlands to slow their stride.

But the research explains that the end was coming for the last of the woolly mammoths, who inhabited Beringia, a chilly region linked by the Bering Strait that included wide swaths of Alaska, the Yukon and Siberia.

Though humans had hunted woolly mammoths in Siberia for millennia, it wasn't until the last ice age that people crossed the Bering Strait and began hunting them in Alaska and the Yukon for the first time. After a harsh, 1,500-year cold snap called the Younger Dryas about 13,000 years ago, the climate began to get even warmer. The rising temperatures led to a decline in woolly mammoths' favored foods, like grasses and willows, and encouraged the growth of low-nutrient conifers and potentially toxic birch. Marshy peatlands developed, forcing the mammoths to struggle through difficult and nutritionally poor terrain, and forests became more abundant, squeezing mammoths out of their former territory.

"It's not just the climate change that killed them off," MacDonald said. "It's the habitat change and human pressure. Hunting expanded at the same time that the habitat became less amenable."

Most of the woolly mammoths died about 10,000 years ago, with the final small populations, which were living on islands, lingering until about 4,000 years ago.

Many previous theories about the mammoths' extinction tended to blame only one thing: hunting, climate changes, disease or even an ice-melting, climate-changing meteor, MacDonald said. The new research marks the first time scientists mapped out and dated so many different aspects of the era at once. Using radiocarbon dating of fossils, the researchers were able to trace the changing locations of peatlands, forests, plant species, mammoth populations and human settlements over time, and they cross-referenced this information with climate-change data.

The research used 1,323 mammoth radiocarbon dates, 658 peatland dates, 447 tree dates, and 576 dates from Paleolithic archaeological sites. Scientists from IoES and other UCLA departments obtained samples and worked on radiocarbon dating of the peatlands and the forests, and they created a database uniting information on hundreds of previously dated mammoth samples, developing the final map from thousands of dates and latitude and longitude records.

That's what drew Van Valkenburgh, a paleontologist and professor of ecology and evolutionary biology, to the project.

"Glen's project combined paleobotanical, paleontological, genetic, archaeological and paleoclimate data and did it in a bigger way, with many more data points, than has been done before," said Van Valkenburgh, who interpreted the archaeological record. "I was excited to be able to contribute to such an ambitious and exciting study."

She and Wayne, a UCLA molecular geneticist and professor of ecology and evolutionary biology who studies ancient DNA, used different methods of examining the mammoth fossils to reconstruct the ancient population size.

"It's a dramatic advance in the amount of data," said Wayne, who reconstructed mitochondrial DNA from radiocarbon-dated woolly mammoth remains. "Essentially, larger populations should have greater genetic diversity. However, in this case, the extent of fossil remains provided a more high-resolution picture of how the population size changed through time than genetic diversity."

Mapping the size and location of both mammoth and human populations alongside temperature changes and plant locations through time gave the researches a uniquely complete view of what happened, MacDonald said.

"We are, in a sense, time-traveling with our maps to look at the mammoths," he said.

It's something MacDonald has dreamed of for a long time, he said. He was working in Siberia several years ago when a colleague found a woolly mammoth tooth.

"We looked at it and held it, and just the thought that those immense creatures had been there not that long ago in geologic time and yet completely disappeared was really amazing," MacDonald said. "How warming in the past has been involved in extinction might help us prevent extinctions in the future."

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NotParker
1.4 / 5 (29) Jun 12, 2012
People still gather around a camp fire and tell ghost stories to scare the kids. But nobody believes them. It appears climate scientists like to tell scary untrue stories too ... so you'll keep giving them grant money.
TS1
4.6 / 5 (10) Jun 12, 2012
"Rising temperatures, ... all contributed to the extinction of the woolly mammoth"

hmmm so how cold was it then BEFORE the temperatures started rising, being that mammoths are found in permafrost with fur and with food in their guts. Meaning their bodies did not decay before they died, or in other words looks like they died in some kind of cold climate event.

Besides that mammoths are related to elephants and probably need to consume similar amounts of food, which is like over 300 pounds per day. Today it would be difficult to find that amount of food in those areas (in Siberia) where the mammoths remains have been found.
HannesAlfven
3.5 / 5 (11) Jun 12, 2012
@TS1

You're critique is dead-on. From Dwardu Cardona in comments within KRONOS, vol. VII, No. 4, (Summer, 1982), page 88:

"Ivory is filled with a gelatinous solution which facilitates its carving and contributes to its high polish. This solution can only be found in fresh and instantly frozen tusks. It does not otherwise survive the ravages of time. Yet the tusks which came from Siberian graveyards were as perfect and in as fine condition as if recently killed.

From Charles Ginenthals' Extinction of the Mammath:

"To be of any use for carving, tusks must either come from freshly killed animals or have been frozen very quickly after the deaths of the animals and kept frozen. Ivory experts testify that if tusks are exposed to weather they dry out, lose their animal matter and become useless for carving" (see Richard Lydekker, Mammoth Ivory, Smithsonian Reports, (1899), pp. 361-366.)
Cave_Man
2.4 / 5 (5) Jun 12, 2012
What happened to those guys who were going to clone the mammoth they found preserved? They enough intact genetic material and were going to clone and implant in an elephant or something. That sounded awesome except of course for the problem of habitat, we would have to provide them with everything. Still, giving life to an extinct species would be pretty awesome if not a little creepy...
Shootist
3.2 / 5 (9) Jun 12, 2012
"Rising temperatures, ... all contributed to the extinction of the woolly mammoth"

hmmm so how cold was it then BEFORE the temperatures started rising, being that mammoths are found in permafrost with fur and with food in their guts. Meaning their bodies did not decay before they died, or in other words looks like they died in some kind of cold climate event.

Besides that mammoths are related to elephants and probably need to consume similar amounts of food, which is like over 300 pounds per day. Today it would be difficult to find that amount of food in those areas (in Siberia) where the mammoths remains have been found.


How cold? Google Lesser Dryas. Cold enough that it reversed the ending of the last glaciation for the 1500 years mentioned above. Ice Age cold. 2 kilometer thick ice sheets west of Boston, cold.
Shakescene21
3.9 / 5 (7) Jun 12, 2012
These researchers conveniently ignored the Columbian Mammoth, which was common in North America until 12,000 years ago and was adapted to more temperate climate. A warmer climate should have benefitted the Columbian Mammoth, but instead they went extinct soon after humans arrived.
NotParker
1.9 / 5 (18) Jun 12, 2012
Human shoot 1,000 polar bears a year. What gets blamed for polar bear population changes - global warming.
PussyCat_Eyes
1.6 / 5 (19) Jun 12, 2012
So, are they saying that there was global warming even without fossil fuel usage? No way, it can't be. Everyone knows that it's only humans that cause global warming....no other reasons need apply.
>sarcasm
Skepticus
2.1 / 5 (9) Jun 12, 2012
At least the mammoth's ivory is usable. Extinct humans' bone is probably only good for grinding up to add a bit of calcium for animal feeds by whatever sentient species a few hundred million years from now. Ah, I forget, their archeologists will find billions of vitrified ceramic religious ceremonial objects (toilet bowls) as a testament of a bygone species..!
epsi00
5 / 5 (3) Jun 12, 2012
Elephants, rhinos, and in general big animals, will go extinct next for the same reason, competition with humans for resources.
NotParker
2.1 / 5 (13) Jun 12, 2012
Elephants, rhinos, and in general big animals, will go extinct next for the same reason, competition with humans for resources.


Shooting them probably doesn't help.
Jonseer
3.7 / 5 (18) Jun 13, 2012
So, are they saying that there was global warming even without fossil fuel usage? No way, it can't be. Everyone knows that it's only humans that cause global warming.....


No climatologist or anyone who understands the concept of "climate change" ever said or inferred - "that it's only humans that cause global warming".

Let me guess you depend on Fox news for climate science.

Climate change IS a NATURAL PROCESS that has happened repeatedly and previously ALWAYS a result of natural events.

These natural climate changes occurred usually on the scale of 10,000s of years or longer.

What the global warming theory says is, because we are pumping the atmosphere full of greenhouse gases we are dramatically SPEEDING UP the "natural process" that usually takes thousands of years and making it happen over a few centuries with dramatic changes visible in a lifetime.

Global warming poses no threat to Earth, but it will result in human catastrophes on scales never seen before.
NotParker
1.8 / 5 (15) Jun 13, 2012
So, are they saying that there was global warming even without fossil fuel usage? No way, it can't be. Everyone knows that it's only humans that cause global warming.....


No climatologist or anyone who understands the concept of "climate change" ever said or inferred - "that it's only humans that cause global warming".

Let me guess you depend on Fox news for climate science.

Climate change IS a NATURAL PROCESS that has happened repeatedly and previously ALWAYS a result of natural events.

These natural climate changes occurred usually on the scale of 10,000s of years or longer.


ENSO is every few years and temperatures can change by .7C.

PDO is on 20-30 years time scales and ocean temperature can change by .5C or -.5C down.

Bond Events are on a 1,500 year cycle.

So why not a 60 year cycle. Up 1910 - 1940 , down 1940 to 1970. up 1970 to 2000. Down 2000 - ????.
Vendicar_Decarian
3.7 / 5 (12) Jun 13, 2012
Science is a scary subject for creationists, religionists, and other forms of denialist.

Fear is what motivates their denial of science and reality.

"It appears climate scientists like to tell scary untrue stories too"

In ParkerTard's case his motivation is a paycheck from the Propaganda industry he works for.

Vendicar_Decarian
3.2 / 5 (9) Jun 13, 2012
I am a firm believer in the idea that a few public hangings will help.

"Shooting them probably doesn't help." - ParkerTard

Vendicar_Decarian
3.7 / 5 (12) Jun 13, 2012
Indiscriminate killing of polar bears with automated kill traps was ended 30 years ago, and since that end, polar bear numbers have increased.

"Human shoot 1,000 polar bears a year." - ParkerTard

However, polar bear numbers are now on the decline overall even though hunting has also declined.

Biologists tell us that the reason is a loss of habitat due to a warming of the north.
ubavontuba
2 / 5 (16) Jun 13, 2012
Indiscriminate killing of polar bears with automated kill traps was ended 30 years ago, and since that end, polar bear numbers have increased.

"Human shoot 1,000 polar bears a year." - ParkerTard

However, polar bear numbers are now on the decline overall even though hunting has also declined.

Biologists tell us that the reason is a loss of habitat due to a warming of the north.
This VDtard lie is easy to disprove:

the bear population is not in crisis as people believed, said Drikus Gissing, Nunavuts director of wildlife management. There is no doom and gloom.

http://www.theglo...2392523/
gmurphy
3.9 / 5 (10) Jun 13, 2012
@ubavontuba, from the article you linked: The survey identified 50 cubs, which are usually less than 10 months old, and 22 yearlings, roughly 22 months old. Thats nearly one-third the number required for a healthy population, he said. This is a clear indication that this population is not sustaining itself in any way, shape, or form.
ubavontuba
1.6 / 5 (14) Jun 15, 2012
@ubavontuba, from the article you linked: The survey identified 50 cubs, which are usually less than 10 months old, and 22 yearlings, roughly 22 months old. Thats nearly one-third the number required for a healthy population, he said. This is a clear indication that this population is not sustaining itself in any way, shape, or form.
First of all, let me say I'm pleased you actually read the reference. So few AGW supporters bother to check the facts.

Anyway, yes, global warming proponent and bear population alarmist Andrew Derocher expressed doubts. But, as he was wrong about the overall bear population, I have little doubt his concerns have little merit. Just because they didn't see tons of cubs in an aerial survey doesn't mean they aren't there. What they did see was a bear population that was "far larger than many scientists thought, and might be growing."

How can that be possible if they aren't sustainably propagating?
HannesAlfven
1.1 / 5 (8) Jun 17, 2012
Re: "Science is a scary subject for creationists, religionists, and other forms of denialist ... Fear is what motivates their denial of science and reality ... "It appears climate scientists like to tell scary untrue stories too""

There's plenty of room for debate on the topic of the extinction of the mammoths. Read Charles Ginenthal's "Extinction of the Mammoth". These debates have been raging for many decades now, and there are extremely good arguments that catastrophe is the main culprit here. But, the problem with this inference is that it also undermines the most fundamental assumption for this entire enterprise -- gradualism. This is the dirty secret to this discipline: That if a large catastrophe played a significant role in the past, then we cannot actually look to the present to decode the past. This creates a natural aversion amongst the practitioners against catastrophism.

Furthermore, it's not entirely clear that the mammoths required cold temperatures for survival.
Howhot
4.4 / 5 (7) Jun 17, 2012
It really was three things that killed off the woolly mammoths. Humans taking over the land, their change in habitat due to the mammoth's exodus and climate change. I see all of DENIERS have just jumped on-board because of the climate change aspect to spin facts into their own delusional models (always funny to see).

In Siberia where they discovered the pygmy woolly mammoths they have been able to demonstrate through archaeological evidence that reduced food resources forced the smaller and smaller sizes. Humans had force the flintsone pacaderms further north. Based on the evidence, our forefathers from that time must have loved to eat the woollies. Then comes the massive and huge end of ice-age climate change and the result is extinction. The woollies just couldn't adapt fast enough or move quick enough to avoid man and the environment.

NotParker
1 / 5 (9) Jun 17, 2012
"Most of the woolly mammoths died about 10,000 years ago, with the final small populations, which were living on islands, lingering until about 4,000 years ago."

6,000 years to die off? I doubt it was climate change. Islands protect species from predators, not climate change.

If anything killed them off it was humans or the big cold drop around 8,000 years ago visible on the GISP2 ice core.

http://joannenova...-swings/

I think the authors just threw in the word "climate change" because they were trawling for grant money.
ryggesogn2
1 / 5 (4) Jun 17, 2012
And the lesson is ... adapt or die.