True causes for extinction of cave bear revealed

Aug 24, 2010
This Ursus spelaeus male skull found in Cova Eiros (Triacastela, Lugo). Credit: Grandal-D'Anglade et al.

The cave bear started to become extinct in Europe 24,000 years ago, but until now the cause was unknown. An international team of scientists has analysed mitochondrial DNA sequences from 17 new fossil samples, and compared these with the modern brown bear. The results show that the decline of the cave bear started 50,000 years ago, and was caused more by human expansion than by climate change.

"The decline in the of the cave bear (Ursus spelaeus) began around 50,000 years ago, much earlier than previously suggested, at a time when no major climate change was taking place, but which does coincide with the start of human expansion", Aurora Grandal-D'Anglade, co-author of the study and a researcher at the University Institute of Geology of the University of Coruna, tells SINC.

According to the research study, published in the journal Molecular Biology and Evolution, dating of the fossil remains shows that the cave bear ceased to be abundant in Central Europe around 35,000 years ago.

"This can be attributed to increasing human expansion and the resulting competition between humans and bears for land and shelter", explains the scientist, who links this with the scarce fossil representation of the bear's prey in the abundant of this species.

In order to reach their conclusions, the team of scientists, led by the Max Planck Institute for Evolutionary Anthropology (Germany) studied mitochondrial DNA sequences from bear fossils in European deposits (Siberia, Ukraine, Central Europe and the Iberian Peninsula, specifically Galicia), and carried out a Bayesian analysis (of statistical probability).

The scientists also made comparisons with the modern brown bear (Ursus arctos) and with fossil samples of this species of bear, and managed to show why one became extinct and the other did not. In order to demonstrate this, the study analysed 59 cave bear and 40 from the brown bear, from between 60,000 and 24,000 years ago for the cave bear and from 80,000 years ago up to the present day for the brown bear.

The decline of the cave bear began 50,000 years ago due to human expansion. Credit: RockCreek

Decline of the caves, extinction of the bears

The impoverishment of ecosystems during the last glacial maximum was "the 'coup de grace' for this species, which was already in rapid decline", the author explains.

The present day brown bear did not suffer the same fate and has survived until today for one simple reason - brown bears did not depend so heavily on the cave habitat, which was becoming degraded, and this is why they did not follow the same pattern as the cave bears.

"Brown bears rely on less specific shelters for hibernation. In fact, their remains are not very numerous in cave deposits", the Galician researcher says.

The definitive extinction of the cave bear "broadly" coincides with the last cooling of the climate during the Pleistocene (between 25,000 and 18,000 years ago), which may have led to a reduction in shelter and the vegetation that the animals fed on.

The cave bear inhabited Europe during the Late Pleistocene and became definitively extinct around 24,000 years ago, although it held out for a few thousand years longer in some areas, such as the north west of the , than in other places. This ursid was a large animal, weighing 500 kg on average, and was largely a herbivore. The bear hibernated in the depths of limestone caves, where the remains of individuals that died during hibernation slowly accumulated over time.

Explore further: Crowd-sourcing Britain's Bronze Age

More information: Stiller, Mathias, et al. "Withering Away-25,000 Years of Genetic Decline Preceded Cave Bear Extinction" Molecular Biology and Evolution 27(5): 975-978, May 2010. doi:10.1093/molbev/msq083

Provided by FECYT - Spanish Foundation for Science and Technology

4.3 /5 (15 votes)

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Modernmystic
2.5 / 5 (2) Aug 24, 2010
So was this a natural or "unnatural" extinction?

:-)
SteveL
5 / 5 (1) Aug 25, 2010
It's only unnatural if humans are involved. Somehow, we don't count - at least to us.
Modernmystic
3.7 / 5 (3) Aug 25, 2010
I do find this argument funny sometimes. It kinda drives the other side nutty in that it gets really hard for them to deny their hypocrisy on the issue.

I've never been able to get a straight answer (that made sense anyway) as to when we became supernatural beings working outside the rules of "mother nature", evolution or whatever you want to call it and no matter what we did on the planet, whether or not it was breathing out CO2, or clear cutting a forest became "bad".

Ultimately mother nature doesn't give a s*** what we do, because "she" is a amoral b**** who's only rule is cutthroat competition at its "ugliest" and who's only principle is success.

Any arguments we have about the environment are HUMAN arguments, and as such no one has an automatic lock on the "moral high ground" in said issues. They're arguments over HUMAN values, desires, wants, and needs. But it is hilarious to see people try to couch them otherwise.
Ethelred
2 / 5 (1) Aug 26, 2010
I've never been able to get a straight answer (that made sense anyway) as to when we became supernatural beings


Never did and I am not aware of anyone that has made the claim. Perhaps that is why you can't get it straight.

However a lot people do have the idea that we don't count. I suppose it came from the religious idea that we aren't animals. It certainly isn't a scientific idea.

However our tools are not natural, in the way almost everyone means by natural, and those bears were often killed by tools. The land has been changed by tools. Agriculture isn't natural. Burning down forests intentionally isn't natural.

They're arguments over HUMAN values, desires, wants, and needs. But it is hilarious to see people try to couch them otherwise.


Ultimately mother nature doesn't give a s*** what we do, because "she" is a amoral b**** who's only rule i


I see a total logical disconnect between those two comments. Amazing that they came from the same person.

Ethelred
Modernmystic
1 / 5 (1) Aug 26, 2010

I see a total logical disconnect between those two comments. Amazing that they came from the same person.


Prithee Mr. Spock, do enlighten...

How is it illogical to recognize "mother nature" as an amoral agent, and human beings as moral agents with values and hence arguments over what mother nature "ought" to be or do...

What's amazing is that you couldn't grasp that simple point...
Modernmystic
3.7 / 5 (3) Aug 26, 2010

However our tools are not natural,


Are they supernatural?

in the way almost everyone means by natural,


Now you get to define what's natural...well then you've already won the argument haven't you. Sorry Eth it's not that easy, prove our tools aren't natural.

and those bears were often killed by tools. The land has been changed by tools. Agriculture isn't natural. Burning down forests intentionally isn't natural.


Are beaver dams natural? Why EXACTLY are we different? Is it just because we're so damn good at it? Sorry I fail to see how that disqualifies our actions as natural. Stamping your feet and saying those actions aren't natural or that "everyone agrees" isn't sufficient. I need a coherent reason, preferably not an emotional plea.
Skeptic_Heretic
not rated yet Aug 26, 2010
However our tools are not natural, in the way almost everyone means by natural, and those bears were often killed by tools. The land has been changed by tools. Agriculture isn't natural. Burning down forests intentionally isn't natural.
So would you say Ants domesticating Aphids is unnatural? Many animals have adapted to use tools. It is no longer considered a human characteristic. We may be able to change the natural world but you aren't doing anything "unnatural" as everything is a component of nature.
How is it illogical to recognize "mother nature" as an amoral agent, and human beings as moral agents with values and hence arguments over what mother nature "ought" to be or do...
Because we're a component of nature which you first acknowledge and then deny. You changed your perspective faster than a professional wet nurse changes a child's diaper. It was amazing to read.
Modernmystic
1 / 5 (1) Aug 26, 2010
Because we're a component of nature which you first acknowledge and then deny. You changed your perspective faster than a professional wet nurse changes a child's diaper. It was amazing to read.


Curious, how did I deny that we are a component of nature?

I merely acknowledge our ability to hold values and morals, and hence have differing views of nature. That we do this does not mean we're not a part of nature, but more importantly nature could "care less" that we do have this characteristic.

Not all things in nature are equivalent. You can't say that a bird's ability to fly is the same as a fish's to swim. Both are a part of nature, but they are very different aspects of nature.
Skeptic_Heretic
4 / 5 (1) Aug 26, 2010
Curious, how did I deny that we are a component of nature?
By implying that our morality is not a component of nature. Technically everything, including ideology is a componenet of nature.
Ethelred
1 / 5 (2) Aug 27, 2010
Prithee Mr. Spock, do enlighten
Are you blind. Nevermind your religious. To be specific:
Hilarity over people fussing over mere human values and that ridiculous bit of anthroporphization of MOTHER NATURE. Well that does conflict Captain Canuck.
Are beaver dams natural?
They aren't human. If you can't see the diference between something beavers do and things that HUMANS do and control then again you have problems with logical thinking. Its a result of thinkging with your religion and politics instead of logic and reason. If you weren't trying to avoid thinking about the messes humans make you wouldn't be trying to avoid using normal English.
Why EXACTLY are we different?
We don't cut down trees with our teeth. Of course in YOUR religious beliefs, as opposed your politics, HUMANS own the Earth and can screw it up any way we want. Ruining it for the next generation apears to be OK by you somehow out of that mishmash of Right Wing and Religious thinking.

More
Ethelred
1 / 5 (2) Aug 27, 2010
Is it just because we're so damn good at it?
We suck at it when it comes to thinking about the future. Well YOU suck it.
Sorry I fail to see how that disqualifies our actions as natural.
I fail to see why you are religious. But if you want to avoid the usual definitions and use one that fits your own political needs then continue. Just don't expect me to along.
Stamping your feet and saying those actions aren't natural or that "everyone agrees" isn't sufficient
YOU are stamping your feet. I am going on ENGLISH which IS a matter of agreement.
I need a coherent reason, preferably not an emotional plea.
I am using ENGLISH. You are using politics. Politics of emotion. In ENGLISH humans are separated from nature in normal discourse. Of course there is little normal thinking going when you want to avoid reality.

We killed the cave bears. Whats your problem with admitting to it? What is your problem with admitting that we can avoid killing of other species?

Ethelred
Ethelred
1 / 5 (3) Aug 27, 2010
So would you say Ants domesticating Aphids is unnatural?


It is an evolved behavior and not tool use.

Many animals have adapted to use tools.


Horse manure. A FEW animals use tools. Even fewer make them. Some crows and some chimps and all they do is bend sticks. Not exactly making steel or even flint blades is it?

We may be able to change the natural world but you aren't doing anything "unnatural" as everything is a component of nature.


Sophistry. That is simply changing the meaning of the word. Natural is almost always used as NOT MAN. If you don't want to use English please tell us first.

Both of you are simply trying to change the meaning of the word Natural to make a point. Oddly enough they DIFFERENT points. You are trying to blend Man and the rest of the world and Modernnmystic is trying to avoid Conservation.

Both of you try using English please. I don't speak Political Expediency.

Ethelred
Skeptic_Heretic
3 / 5 (2) Aug 27, 2010
Horse manure. A FEW animals use tools. Even fewer make them. Some crows and some chimps and all they do is bend sticks. Not exactly making steel or even flint blades is it?
Your showing deep ignorance here. Capuchin monkeys in south america have been found shaping anvil stones, primarily utilizing selection and exaggerated use in order to crack palm oil nuts. If you want to call that "bending sticks" and consider only bladed items to be "unnatural tools" then you're simply showing the fact that you're stuck in a mindset that's rather out of date.

We're going to have to agree to disagree. And you can take your Political Expediency statement and stick that right back where it came from.
Modernmystic
1 / 5 (1) Aug 27, 2010
Curious, how did I deny that we are a component of nature?
By implying that our morality is not a component of nature. Technically everything, including ideology is a componenet of nature.


A component of nature yes, but it is not nature itself, which was the point I was making.
Modernmystic
1 / 5 (1) Aug 27, 2010
There's no point in "debating" Eth on this one, his religion is nature. I can see that with crystal clarity now, and human beings play the part of Mephistopheles in his divine delusional comedy.

BTW,

Natural:

existing in or in conformity with nature or the observable world; neither supernatural nor magical; "a perfectly natural explanation"

Again that's English, use it, it's another one of those neat tools we human beings have.

I have no problem admitting we killed the cave bears, I have a problem with someone saying it's unnatural like they have some divine insight on what nature SHOULD be rather than what it IS.

YOU are the one using politics...no scratch that, a thinly veiled religion, to justify your views on human beings and their place in the natural world.

The fact that we can make moral judgments about nature and argue with each other over said judgments is natural too, but that doesn't mean that nature is taking your side because humans are somehow "unnatural".

Modernmystic
1 / 5 (1) Aug 27, 2010
BTW if you want to have a HUMAN discussion about the environment with me and my thoughts, values, and feelings on it I'd be glad to rather than you ramming words in my mouth Eth.

What I REFUSE to do is have a "debate" with a fanatic who thinks he's automatically right about everything environmental if he simply argues that humans are "wrong" and "unnatural" as a starting premise...
Gawad
5 / 5 (1) Aug 27, 2010
IMHO, the use of "supernatural" in such a context just muddies the water as it too strongly connotes of magic, the unexplainable or of somehow operating outside nature. These are all notions I don't think can bring much to a scientific discussion. I do think it may be more useful to treat humans as a "meta-species". While we certainly can't help but operate within the bounds of the natural world and be confined to the laws of physics (therefore anything we do can be seen as "natural") it certainly seems like we have been moving away from what can be termed "intrinsically natural" behavior, i.e., hunting and gathering towards the sort of behavior that contributes to our impression of being separate from nature, especially starting with agriculture and greatly amplified by industrialization. We may well be the species with the greatest capacity to change the Earth since the Great Oxygenation Event...with the important difference that we can "step outside ourselves" to plan our actions.
Modernmystic
1 / 5 (1) Aug 27, 2010
I agree we have it within our power, or soon will, to radically change the environment of our planet.

I vehemently disagree that "nature" has an opinion on the subject.

I do, I think most people do...but they are just opinions...ALL of them. I've yet to see any objective evidence that someone is nature's personal spokesperson.
Ethelred
1 / 5 (1) Aug 28, 2010
There's no point in "debating" Eth on this one, his religion is nature.


Thank you MARJON for giving me a religion. I so desperately needed one.

That is a ridiculous statement.

You were HIGHLY selective. Carefully avoiding anything that might show I was using real English.

Natural:

existing in or in conformity with nature or the observable world; neither supernatural nor magical; "a perfectly natural explanation"

Again that's English, use it, it's another one of those neat tools we human beings have.


Please do so. I NEVER claimed we are supernatural and don't care for people putting words in my mouth. That definition says nothing about HUMAN actions.

More
Ethelred
1 / 5 (1) Aug 28, 2010
http://www.merria.../natural
10
a : growing without human care; also : not cultivated

b : existing in or produced by nature : not artificial

b : living in or as if in a state of nature untouched by the influences of civilization and society
a : closely resembling an original : true to nature b : marked by easy simplicity and freedom from artificiality, affectation, or constraint c : having a form or appearance found in nature
I think covers what I said quite well.
I have a problem with someone saying it's unnatural like they have some divine insight on what nature SHOULD be rather than what it IS
I am not the one claiming divine insight. YOU are the religious one. SH is confused I suppose.
YOU are the one using politics...no scratch that, a thinly veiled religion,
Horse manure. I have no religion and nothing in your posts, nor mine, supports that statement.

More
Ethelred
1 / 5 (1) Aug 28, 2010
to justify your views on human beings and their place in the natural world.


Please look at the OTHER parts of the definition of NATURAL.

NOT ONCE have I claimed that humans are supernatural and it is ludicrous to claim that I of all people would make such a ridciulous claim.

You two, or three based on the ranking, simply don't get the idea of NATURAL in the course of normal human discourse.

There are THREE sets and NOT two in this discusion. You are guys are engaged in a false dichotomy.

Three ways of normal human speech next.
Ethelred
1 / 5 (1) Aug 28, 2010
NATURAL - that which is normal if humans AREN'T messing with things. Natural food for instance as oppose to the diet coke I drink. I notice that all the formal definitions broke the rules of formal definitions, they used the word NATURE in the definition of NATURE. Recursive definitions are supposed to be a no-no.

SUPERNATURAL - That which does not conform to the physical laws of the Universe. Ghosts, raising the dead, violating the Second Law of Thermodynamics. Humans only do those things in fiction so we are not supernatural and it is completely false to say I made such a claim.

NEITHER OF THE ABOVE - Human intervention in the normal course of affairs. Like making stone knives. Or artificial sweeteners or diamonds.

By the standards you three are trying to force in this argument there is no such thing as artificial anything. Tanks and guns are natural by that standard. I don't think many here or anywhere else would make such a claim.

Ethelred
Ethelred
1 / 5 (1) Aug 28, 2010
BTW if you want to have a HUMAN discussion about the environment with me and my thoughts, values, and feelings on it I'd be glad to rather than you ramming words in my mouth Eth.

What I REFUSE to do is have a "debate" with a fanatic who thinks he's automatically right about everything environmental if he simply argues that humans are "wrong" and "unnatural" as a starting premise...


That is pretty hypocritical from someone that pretty much completely made up my position on this.

The only thing I did with YOU is to assume that you went the DOMINION over the Earth stuff in tbe Bible. If you don't actually believe in that part of the Bible then I do apologize for the assumption.

I DO NOT apologize for being pissed of at people that make up things and pretend I said them.

Ethelred
Ethelred
1 / 5 (1) Aug 28, 2010
Your showing deep ignorance here.


Your ignorance of my knowledge is overweening.

Capuchin monkeys in south america have been found shaping anvil stones, primarily utilizing selection and exaggerated use in order to crack palm oil nuts


Selection is not creation. By the way otters do that too. They have favorite stones.

If you want to call that "bending sticks" and consider only bladed items to be "unnatural tools" then you're simply showing the fact that you're stuck in a mindset that's rather out of date.


Thank you for knowing all about my mind set. I appreciate knowing that I knew things that I never knew I knew. It is so comforting.

Thank you for turning an example to something else entirely.

Bending sticks is barest fringe of tool making. It is closer to improvisation than a planned event that humans usually engage in when making tools.

Ethelred
Skeptic_Heretic
1 / 5 (1) Aug 28, 2010
By the standards you three are trying to force in this argument there is no such thing as artificial anything. Tanks and guns are natural by that standard. I don't think many here or anywhere else would make such a claim.
Now you're assuming my standards.

My standard for natural or unnatural is based on natural affinity. A great many things that are "man-made" would never appear in nature. Nitrogen Trifluoride for example. Those would be, "unnatural". A tank would be "unnatural". Your examples above are speaking to crude instruments, ie: bladed edges, which we quite often found in nature.
Modernmystic
1 / 5 (1) Aug 28, 2010
LMFAO

Weren't the two of you flicking me s*** earlier because you THOUGHT I had claimed that human judgments and morality (and by association human intellect) was unnatural?

Time to s*** or get off the pot here boys. Now once and for all are human beings and their abilities natural or unnatural? There is no third option here Eth, despite how much you NEED there to be to help prop up your environmental godhead.

Nitrogen Trifluoride is just as natural as anything else if it came from a natural process, and unless you believe in the supernatural then ALL processes are natural, there is no third option. There can't be anything that is unnatural in the worldview of an atheist or an agnostic, this has been my point all along.

It's blithering hypocrites that want it both ways, humans are "natural" animals yet because they're so successful are somehow unnatural and therefore "bad" for nature that are being intellectually dishonest here.
Modernmystic
1 / 5 (1) Aug 28, 2010
There is no "neither of the above", it's unmitigated, unsubstantiated, illogical, bull****.

Sorry the only self consistent position here is that we, and all we do proceed from the natural self consistent, laws of this universe and hence BY DEFINITION are natural, or we're something different.
Talk about English all you want Eth, but throw some logic in there too.
Modernmystic
1 / 5 (1) Aug 28, 2010
As an aside I find it funny that Eth can argue communism is a religion (or at least could be) on another thread, and yet somehow fanatical (and yes based on the tone of your posts I'm about 70% convinced you fall in this camp) environmentalism is exempt?

Oh wait sorry don't want to put words in your mouth...I should ask...CAN environmentalism be a religion too Eth?

Since "we" like to talk about English I'm just wondering if every ism you run in to at some point doesn't get the moniker of religion at some point...
Husky
not rated yet Aug 29, 2010
i would say everything including moral and some of our self destructive tendencies or trading longterm survival of our species as a whole in favour for short term gains of the individual or a small group of individuals are all natural, as is somewhat broader more durable (higher moral?) notion of developing policies to aimed at a sustainable future/global environment to protect our species as a whole
Skeptic_Heretic
not rated yet Aug 30, 2010
It's blithering hypocrites that want it both ways, humans are "natural" animals yet because they're so successful are somehow unnatural and therefore "bad" for nature that are being intellectually dishonest here.
Step back now. NF3 has no natural occurance on earth, which means, using the laws of nature we make it technologically. Don't go all silly extremist on the definitions now.
Modernmystic
1 / 5 (1) Aug 30, 2010
Step back now. NF3 has no natural occurance on earth, which means, using the laws of nature we make it technologically. Don't go all silly extremist on the definitions now.


Is technology unnatural? If so, why?

This is exactly why I said NF3 is a perfectly natural outcome of the laws of the universe. Intelligence (an obviously naturally occurring phenomenon in the universe), whatever form it takes, might make NF3 at some point, therefore NF3 is just as natural as H2O.

Call it artificial, or "intelligently crafted" if it makes you feel better, but whatever else it is it's not unnatural in the context we've been using...period.
Modernmystic
1 / 5 (1) Aug 30, 2010
Perhaps this might even clarify my point better...

Just because intelligence or technology is applied to something doesn't make it unnatural since intelligence and technology are, themselves, natural.

If someone has a logical and self consistent explanation as to how applying one natural process to another makes the latter unnatural I'm all ears.
BuddyEbsen
not rated yet Sep 01, 2010
"When I was a kid my favorite relative was Uncle Caveman. After school we'd all go play in his cave, and every once in a while he would eat one of us. It wasn't until later that I found out that Uncle Caveman was a bear."

Jack Handy

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