Any number of factors 50 million years ago could cause an animal to change, but surely CO2 must be the culprit according to these folks. They don’t even have a picture of the darn thing I can find. But read the abstract after this story for a surprise. – Anthony
From a UFL press release:
UF study shows carnivore species shrank during global warming event
GAINESVILLE, Fla. — A new University of Florida study indicates extinct carnivorous mammals shrank in size during a global warming event that occurred 55 million years ago.
The study, scheduled to appear in the December print edition of the Journal of Mammalian Evolution and now available online, describes a new species that evolved to half the size of its ancestors during this period of global warming.
The hyena-like animal, Palaeonictis wingi, evolved from the size of a bear to the size of a coyote during a 200,000-year period when Earth’s average temperature increased about 15 degrees Fahrenheit. Following this global warming event, Earth’s temperature cooled and the animal evolved to a larger size.
“We know that plant-eating mammals got smaller during the earliest Eocene when global warming occurred, possibly associated with elevated levels of carbon dioxide,” said lead author Stephen Chester, a Yale University doctoral student who began the research at UF with Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History. “Surprisingly, this study shows that the same thing happened in some carnivores, suggesting that other factors may have played a critical role in their evolution.”
Researchers discovered a nearly complete jaw from the animal in Wyoming’s Big Horn Basin in 2006 during a fossil-collecting expedition, led by Bloch, a co-author on the study. Bloch said the new findings could help scientists better understand the impact of current global warming.
“Documenting the impact of global climate change in the past is one of the only real experiments that can inform us about what the effects global warming might have on mammals in the near future,” said Bloch, who has studied this climate change event for nearly a decade.
Scientists think the Earth experienced increased levels of carbon dioxide and a drier environment during the warmer time period, but they do not completely understand what caused mammals to shrink.
One theory is that carbon dioxide levels reduced plant nutrients, causing herbivorous mammals to shrink. The newly described species primarily consumed meat, meaning plant nutrients couldn’t have been the only factor, Bloch said.
Mammals in warmer climates today tend to be smaller than mammals in colder climates, Chester said. For example, brown bears in Montana are generally smaller than those found in Alaska.
The study’s other authors are Ross Secord, assistant professor at the University of Nebraska, and Doug Boyer, assistant professor at Brooklyn College.
Bloch said a tooth from this animal was described in a paper about 20 years ago, but scientists did not have enough information to name the new species until finding the jaw.
The species was named after Scott Wing, a paleobotanist at the Smithsonian National Museum of Natural History. He studies the impact the global warming event had on forests in the past, and has played an important role in the collaborative research in the Big Horn Basin, Bloch said.
=======================================
Only one problem, here’s [the abstract] saying CO2 had nothing to do with it:
A New Small-Bodied Species of Palaeonictis (Creodonta, Oxyaenidae) from the Paleocene-Eocene Thermal Maximum
Abstract
Of course, Real Climate thinks the PETM is “weird” so pretty much anything goes I suppose if you can link anything in that period to CO2 somehow.
Re comment 8:
“extinct carnivorous mammals shrank in size”
Poorly worded indeed…. Unless they are talking about erosion of fossilized skeletal remains 🙂
>>Recent research has shown that plants produce more growth and higher nutrient levels
>>with high atmospheric CO2 levels. Were plants 15ma years age so different to today’s?
plants may have been similar, but ecosystems were different. Nowdays, we have huge territories covered with herbaceous plants. But as co2 increases, two things happen : plants then can live in more arid environment, and to save water they become more rigid and less edible and chewable; secondly, with more plant food available, more plants come and by competition they create forest, where most of the increased productivity spent on producing wood – not the best food you can think of – it is mostly consumed by fungi … i think termites managed to use some kind of bacteria to digest it for themselves
bubbagyro says:
August 25, 2010 at 8:37 am
Bill Illis says:
August 25, 2010 at 5:58 am
Bill, it is more than that. In the Jurassic we had thousands of ppm of carbon dioxide and a very hot global climate. Plants grew at a very high rate thus satisfying the huge appetites of the herbivores like Diplodocus that enabled the large predators to exist. The size of animals is directly proportional to food supply, which is dependent upon CO2 levels.
——————
The megafauna of the last ice age lived in a world of CO2 at 185 ppm to 200 ppm.
In fact, the C3 plants were starved of CO2, especially in areas where it was dryer.
Actual science is always different than the news release and the global warming version.
You’ve got to love these guys, one hand does not know what the other is doing or saying:
“the earliest Eocene when global warming occurred, possibly associated with elevated levels of carbon dioxide,”
” Earth’s temperature cooled and the animal evolved to a larger size.”
So elevated CO2 wasn’t such a great climate forcer or insulation after all…….
It’s already been said, I’m sure, but the extreme prejudice against CO2 is making even people who ought to know better say the most illogical things. Mammals in colder regions are always larger in body mass than their brethren in warmer areas because a larger body is better able to withstand the cold. This goofy mindset reminds me of the people who forward those e-mail warnings about all kinds of common, everyday things that are supposedly going to kill you. (Remember the baby carrots?) Anyone who gives a half-second thought to the logic would immediately recognize it as pure nonsense and not repeat it. There are many people who find it easier to blindly accept what they’re told rather than understand it for themselves. It’s really dispiriting to see how many people are willing to be duped. I don’t know whether they’re lazy or just trusting.
O my gosh! This is a stupid paper based on a jawbone and a tooth!! It is no wonder there is so much speculation. But the speculation! Surely, if the plants greatly declined in nutrients, a smaller animal would be unable to extract sufficient nutrients from the larger volume of “roughage” that has to be digested. Surely this is why herbivores in drier impoverished environments (dry savannah: rhino, giraffe, elephant, wildebeest, hereford cattle, camel …) are built to eat a lot and the fibrous vegetation requires strong chewing, some with chambered stomachs for digestion, long legs, etc. As for the carnivores, all they need is enough herbivores to be well fed – whatever the vegetation. The many commenters also pointed out that there are no simple factors controlling body size. This is an unequivocal thumbs down and I’m only a geologist/engineer.
So a single jawbone provides insights into 200,000 years of evolutionary history? Nebraska Man anyone?
—
A number of comments have run along the line of what kernels had posted at 2:30 PM on 25 August, writing:
“So a single jawbone provides insights into 200,000 years of evolutionary history?”
Not really. But that bone fragment can readily provide information on that particular critter – and it’s possible to infer that said critter is a specimen representative of its species – which accurately reflects its stature (size), developmental maturity, nutritional status, and the environment in which it lived and died.
Hell, look at what can be told by drawing about 10 cc of blood from kernels‘ own basilic vein.
The investigators in this particular study screwed the pooch in a number of glaring and wonderful ways, bowing down to the AGW fraud. Doubtless, they did it to get (and secure yet more) grant funding, which is the Number One priority of all research perniciously dependent upon the fruits of extortion perpetrated by government thugs.
But figuring out what that “single jawbone” could reliably tell about the individual creature of which it was a residuum was pretty much in accord with what has become standard operating procedure in the discipline. Insofar as that part of the study went, the idiots who authored this paper were on solid ground.
It would be deeply appreciated if people who don’t know a goddam thing about comparative anatomy, paleontology, and the techniques involved in getting reliable inferences out of the analysis of information teased from even relatively small fragments of fossilized bone and dentition would just put a cork in it.
You’re stinkin’ up the joint.
—
Bill Illis says:
August 25, 2010 at 11:48 am
The ice age was thousands of years ago, not millions ago, as when the dinosaurs inhabited Earth. The mammal megafauna were adapted to the last glacial about 30 to 15 thousand years ago. They went extinct for a different reason. 300 to 100 millions of years ago the Earth had CO2 in the thousands of PPM. Cycads and ferns grew at enormous rates, creating much of the oil deposits we have today.
My money is on Gaia just trying out some new recipes to see what she can cook up. And since she always gets the right answer; it turns out that what she cooked up worked better than what she had before, so she kept getting orders for the newer slimmer models.
I don’t know about where you live; but some of the species walking around silicon valley; have more in common with horses; and I would not expect them to come out the winners in Gaia’s latest bake-off.
And they aren’t necessarily all home grown either. More than a statistically insignificant number come from places where a surfeit of edible foods is not the normal situation. So it could be that a sudden availability of virtually unlimited food supplies, has evolved new omnivorous species that are on the expansion mode again.
But not to worry; Gaia knows when to put her foot down and stop a dead end street in its tracks.
coturnix19 says:
August 25, 2010 at 10:48 am [ … ]
coturnix19, rather than giving the first opinion that occurs to you, you could try to find out if more CO2 is beneficial to life on Earth:
click1
click2
click3
click4
click5 [See “Key Findings” at upper left of page]
click6 [Disregard the ozone spin. The reason is higher CO2 levels in cities]
click7
click8
Even though you can see that more CO2 is very beneficial for the biosphere, you might be arguing for reasons that have nothing to do with science. I trust not. But if you are, please explain why the actual culprits are not the target of the CO2=CAGW crowd’s ire.
“Scientists think the Earth experienced increased levels of carbon dioxide and a drier environment during the warmer time period”
How do they get away with assuming that warmer means drier? Warmer means more evaporation from the oceans and more precipitation – it does not make any sense.
Rich Matarese says:
August 25, 2010 at 2:58 pm
Could you please explain how so much is teased out of so little and why this is standard operating procedure is acceptable science?
-Scott
—
At 2:58 PM on 25 August, Scott asks:
“Could you please explain how so much is teased out of so little and why this is standard operating procedure is acceptable science?”
Hm. Ought to be obvious, but what the hell. Consider what somebody competently versed in human osteology can do with an analogous fragment of bone recovered from a corpse.
Fossilized remnants are a bit different, but not that much.
If you know the anatomy of other members of the species in question (and of species related thereunto), it’s possible to assess structural characteristics of the specimen you’ve got an draw reliable inferences about the individual creature from which the fragment came. Developmental changes tend to be pretty consistent, so telling the degree of maturity is readily possible – and that’s particularly true if you can recover specimens of the creature’s dentition.
This isn’t my field. I’m a country GP, not a forensic pathologist. But if I hand a recognizable fragment of a mandible or maxilla from a pretty well completely composted human corpse to one of those lab guys, I can be reasonably certain that he’s going to be able to tell me quite a bit about what that cadaver had looked like in terms of stature, age, and general nutritional status. I might even expect some good idea of certain diseases from which he/she might have suffered.
Any contention that the examination of the fossilized remnants upon which the paper presently under discussion is based can reveal much of significance with regard to atmospheric carbon dioxide concentrations prevailing during the life of the animal from which the specimen was derived is, on the face of it, bullpuckey.
But telling whether that particular animal was larger or smaller at maturity than the normal run among its species in other times or places? Not a problem.
—
Rich Matarese says:
August 25, 2010 at 6:25 pm
True enough assuming one knows what the average mature size/form are, but how do we know here? If it’s truly from 50 million years ago, what’s the uncertainty in the age? I would wager it’s quite large (some would disagree, but beyond the instrumental uncertainty is the uncertainty of the assumptions going into radiometric dating where even a fraction of a percent can mean a huge difference in time). Even if only a few hundred thousand years uncertainty and I’d say that’s enough to derail the whole thing, because even if we knew the average size (and other factors) at 50.000000 million years, there’d be too much uncertainty in the age of this specimen to say for certain how it compares. If I’m to believe we diverged from chimps ~300000 generations ago and we’re quite different from them, I simply can’t believe that any reasonable conclusions can be made on something where the uncertainty on the age might be that large.
-Scott
Hmm?
Sumatran tiger ~ 300 lbs.
Siberian tiger ~ 700 lbs.
Guess there’s more CO2 in Sumatra.
Scott
August 25, 2010 at 5:43 pm
The study of mammalian teeth is a complete science unto itself. Am incredible amount of information is encapsulated in a tooth. Most mammals are known by their teeth. And it is not just a single tooth, but a tooth placed in context with millions of other teeth, correlated with other skeletal remains, and complete living specimens of creatures that till exist. There is a lot more science here then you will find in many other places. That is because nothing is ever really settled. For example, the move from hypercarnivor to hypocarnivor and back leaves convoluted clues. Different technique yield different results. Palaeomammalogists generally don’t say “This is the way it is”, but rather “This is the way things are looking right now, but this is also a possibility, and this all might change because of the research Dr. Dave is doing.” I can not remember the last time I read a paper that presented only one possible cladogram.
If you are truly interested, any, and I mean any, text on mammalian palaeontology, will teach you about teeth.
My guess is that you are not.
@bubbagyro says:
August 25, 2010 at 4:02 pm
Cycads and ferns produced the great COAL deposits of the world. Little wee tiny things growing in the ocean produced the material for the OIL and GAS deposits. Amazing isn’t it? We’re told these little wee tiny things are dying off today ‘cuz the CO2 today is so high. So why were they so prolific back, say, 350 million years ago, when CO2 might have been 10x-20x as high? Mysteries abound!
DesertYote says:
August 25, 2010 at 7:01 pm
Again, I don’t doubt this for relatively modern times where a lot is known of current diets, conditions, etc. But when we’re talking about what supposedly happened 50 million years ago how can such certainty be given? I’m not even questioning that the specimen can be determined to be an adult…but how can we know how this specimen compared to the normal at the time when (a) we don’t know the age with that much certainty, and (b) we don’t know the normal specimen for the time.
You’re willingness to openly speculate on motives is interesting.
-Scott
Australia is currently boasting about the Size of it’s members members. That is, the penis size of it’s politicians – at least that’s what I can gather from all this talk of a hung parliament. 😐
—
At 6:25 PM on 25 August, Scott writes:
“True enough assuming one knows what the average mature size/form are, but how do we know here? If it’s truly from 50 million years ago, what’s the uncertainty in the age? … Even if only a few hundred thousand years uncertainty and I’d say that’s enough to derail the whole thing, because even if we knew the average size (and other factors) at 50.000000 million years, there’d be too much uncertainty in the age of this specimen to say for certain how it compares. …I simply can’t believe that any reasonable conclusions can be made on something where the uncertainty on the age might be that large.”
Okay, let’s recapitulate the first sentences of the abstract incorporated in this blog post (above):
“Oxyaenid creodonts are extinct carnivorous mammals known from the Paleogene of North America, Europe, and Asia. The genus Palaeonictis is represented by three species that together span the late Paleocene to early Eocene of North America, and at least one species from the early Eocene of Europe. ”
Read the rest above. Bear in mind that this particular Palaeonictis wingi (the newly-named species discussed in this paper) was a specimen of an extinct predator order also known as the hyaenadonts, of which I take note because of an interesting article I’d read some years ago which argued that they might have gotten pressured out of their ecological niche by the fissiped predator species (particularly the canidae and felidae) because the hyaenadonts’ peculiar dentition imposed upon them a genetic coding burden that reduced their reproductive fitness relative to those successor predators.
Now, “Researchers discovered a nearly complete jaw from the animal in Wyoming’s Big Horn Basin in 2006 during a fossil-collecting expedition, led by Bloch, a co-author on the study,” and with that much of a remnant – given what is well-established with regard to the anatomy of the various creodont species – telling how big this particular critter had been could not be much of a problem, no matter what Scott can or “can’t believe.”
The level of uncertainty ain’t much more here than is the level of uncertainty I’d have in reading Scott‘s own current complete blood count or serum chemistry study’s results. There are a lot of hyaenodont fossil jaws in the bone boxes upon which the paleontologists can and do base their comparative analyses of the specimen they’re now calling P. wingi.
As for dating the particular specimen to within “a few hundred thousand years’ uncertainty,” some attention has got to be paid to the way paleontologists use sedimentary position (and the stuff found in the same layer as the harvested fossil) to set the temporal context in which the critter had lived.
Yeah, a lot of stuff has to be inferred. But as in medical diagnosis, the bone hunters pull in information from a lot of sources upon which to predicate their conclusions, matching what they find in one particular specimen – this fragment of jaw, for instance – against what they know from other evidence. It’s very much a practice of aggregating facts that might seem to the uneducated to be disjointed and unreliable.
Well, hell. A lot of the people who watch House are as the beasts that perish when it comes to the pathological basis of disease and why the protagonist’s seemingly out-of-the-blue differential diagnoses actually make a helluva lot of sense.
Look, Scott, when you were watching the movie A Few Good men, did you wonder for one goddam minute why Santiago died in that fairly routine blanket party at the outset of the movie?
I remember shouting: “G6PD deficiency!” at the screen when the pompous Navy medical officer was being examined during the court martial. Simple blood test, and if Santiago was un borincano (as I suspected he might be), there’s plenty of glucose-6-phosphate dehydrogenase deficiency in that population. G6PD deficiency might readily have accounted for Santiago’s presenting symptoms and the way in which he’d died.
Even a country GP knows that much. That M.O. was professionally remiss in not examining that Marine and securing the diagnostic information that probably would have resulted in a medical discharge. And the lawyers for the defense were negligent in not insisting on a second autopsy. You can bet your butt that a competent forensic pathologist wouldn’t have missed that diagnosis.
But then the movie wouldn’t have had much point, would it?
The UPI press release quoted above tries to play the publication of this paper as propaganda promoting the carbon dioxide forcing premise behind the AGW fraud, and that’s about what I expect from ex-Journalism school schmucks. Too stupid and too lazy to take any real science courses in college.
—
Scott
August 25, 2010 at 7:27 pm
“You’re willingness to openly speculate on motives is interesting.”
Sorry about that, I guess I’m a bit cranky today and I over-reacted to your last sentence.
50 million years is actually pretty recent and there is a lot of material from that time, the Eocene epoch, enough material to in fact discount much of the paper as related in the press release. For one thing, the Eocene was Warm and Wet, not dry. For another, many animals were adapting to living in the forests that were replacing the savannahs, thus becoming smaller.
As for the specimen being normal, though it is not unheard of, dwarfism is incredibly rare, so in all probability it is normal. Of course erecting a species on a single specimen, is far from ideal, it is sometimes all that is available. The problem is that a single species in a genus that is represented by only three known species, tell us very little. Not enough to place any confidence in any supposed evolutionary trajectory. At best, this critter is just a very tiny bit in a much, much larger picture. Making any inferences from it is just plain silly.
I am getting over a flu and am having a nasty head ache, or else I would hunt down an example of a well researched paper that highlights how mammalian palaeontology is done. The author is Xiaoming Wang (no its not a joke name!). Its on the evolution of North American Canines. It is a bit dense, but it is real honest to goodness science. It also has a lot of drawings of teeth 🙂
Once again, my apologies,
-DesertYote
Rich Matarese says:
August 25, 2010 at 7:42 pm
Your response seems to be a bit aggressive, but maybe I’m reading your tone wrong. It is hard to get the tone from an internet comment.
What I’m questioning is not “telling how big this particular critter had been”, but relating its size to what it would be in relation to (a) the average at that particular time and (b) what it would be with lower CO2. I’m sorry I did not make that clear. Thanks for bringing up that it was dated by sedimentary position, as that just adds to the uncertainty I was questioning.
You reference a medical diagnosis, and that analogy is representative of what I’m questioning. When the uncertainty in the age of the specimen is so high, how can so many inferences be made? You say the uncertainty is similar to that of an analysis done on my own blood/serum, but as a person that works with calibrations and uncertainties on a fairly regular basis, there’s just no way that’s possible. The discrepancy in the number of calibration points and the knowledge gained from the sample (DNA etc versus a mineralized body part of unknown age) is immense.
I don’t watch House and I never saw A Few Good Men either, so that part of your post is lost on me. The only comparison I might understand is the TV show Bones, which I’ve watched a fair amount of. Dr. Brennan obtains a ton of information from the bones of deceased (or even alive) individuals. But the thing is she has an enormous population of known bones (guaranteed to be from the same specie and time) in which to form her calibration curve if you want to call it that. However, I know that quite a bit in that show can be exaggerated, as my area is close enough to Dr. Hodgins’ to know when they’re producing BS in that area and assume they do it in the other areas too.
As to “real” sciences, I’m not sure I know what you mean there. In my field, that would basically be limited to “hard science” areas like physics or chemistry and not something like paleontology.
-Scott
DesertYote says:
August 25, 2010 at 8:41 pm
Thank you for the nice response. In rereading my post, my last sentence came across totally wrong and I apologize. It should have said something more along the lines of “Making determinations of average species size and its relationship to carbon dioxide in light of the large uncertainties and many assumptions is pretty doubtful.”
In general, my scepticism of the quality of radiometric dating has me sceptical of any of this, but I did learn from your post, so many thanks.
I hope you recover from your illness soon,
-Scott
“Mammals in warmer climates today tend to be smaller than mammals in colder climates, Chester said.”
I wonder why…? Haven’t read the full article, but I have to wonder if they took into account that body size and body temperature (for mammals) are related. That’s due in large part because the surface/volume ratio changes with size and directly affects a mammal’s ability to maintain its core temperature in response to environmental temperature stress.
So it looks like heat stress causes animals to adapt by reducing size in order to increase cooling efficiency and in some cases reduce water loss. Who’da thunk it?