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.
A New Small-Bodied Species of Palaeonictis (Creodonta, Oxyaenidae) from the Paleocene-Eocene Thermal Maximum
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Could it be that the warming caused an increase in animal life, maybe less deaths from the cold, (remember iguanas falling from trees during this winter’s Florida freeze, dead fish in frozen rivers in S. America?) and thus there was more competition for the same amount of plant food? Just thinking.
How did earth come out of the period of global warming with out Kyoto and cap and trade?
So gray-skinned extra-terrestrials with oversized heads and bodies the size of children must come from an industrially polluted and overheated planet. They genetically engineered themselves to maintain big heads to preserve their intelligence. And now they are here on Earth to steal our women (to cook for them). It all works.
Mammals adapt to colder climates through increasing body mass?
Wow. Who would have guessed that reduced surface area to body mass ratio would help a furry friend stay warm on cold winter night.
Let me take a wild guess about the next great discovery. Mammals adapt to colder climates through thicker fur too.
No wait. It must be a response to lower CO2 level. It has nothing to do with the physics of heat retention. Greater body mass and more fur means there’s more carbon in the animal. With less carbon in the air it is natural to sequester more carbon in the body so in case the carbon in the air runs out completely the animal will have a larger store of emergency carbon. Yeah, that’s it. That’s the ticket.
No wait. It’s not related to
Why is it that today’s kids, living on a diet of burgers (carnivorous diet) and Coke (full of CO2) end up 6 ft tall and more? LOL. Is it the CO2? Yes most probably, but I need researching to prove it. Now can I have that grant please? A million dollars would suit me very well thank you.
Apparently Walmart reduces the CO2 content in the air to almost nil.
Metryq,
That makes sense, since the Earth was much smaller in the past. The Earth is facing the same ecological catastrophes as other doomed civilizations. We may have to relocate to another planet. Fortunately, there is solid evidence proving that there is water on Mars.
This is all true, as I have it on the best authority [source].
40 million years earlier, it was 3 or 4C warmer than the PETM and what did we have, the biggest land animals that ever lived.
There really isn’t a correlation between size and climate. We’ve had giant animals in cold climates and warm climates.
I’ve noticed that the climatologists have an unusual/unhealthy fascination with the PETM when there are hundreds of other rapid climate changes that are ignored.
Can it really be a scientific study without a global warming hook in it. Or an evolution claim.
And these people are ‘scientists’?
I realize there are many things that affect size but even I have a decent explanation for some of the variation with temperature, and CO2 isn’t involved.
Surface area of a solid increases as a square function but volume of the same solid increases as a cube function. Heat is generated by the volume of muscle and excess heat is lost through the surface area. So a larger animal in a cold climate has a easier time staying warm due to less heat loss, while in a warm climate a smaller animal has an easier time staying cool due to more heat loss.
Obviously this is a generalization. There are successful small animals in cold places and successful large animals in warm places.
Don’t forget, birds are also getting smaller….
So, 15 degree change, and there was no mass die-out. Why are we worried about a 1/2 degree c change?
Chris says: August 24, 2010 at 10:28 pm: “…maybe the herbivores evolved to smaller sizes because of reduced nutritional quality of vegetation which happens with an increase in CO2 availability to plants.”
So are you suggesting that more CO2 fertilisation = less nutritional content in plants? Or is it another one of those old inverted “U”s – in other words, is there an optimal CO2 concentration whereby either increasing or decreasing the level leads to poorer plant nutrition? If so, when was the optimal level? My money’s on the 1950s, when everything was perfect and the world was one big Happy Days episode. Or alternatively, it might all be complete and utter BS.
Lysenkoism lives. Our theories will meet our political needs, science be damned.
KW
Sonicfrog: August 25, 2010 at 7:02 am
Don’t forget, birds are also getting smaller…
That’s because birds are carnivores, except for the ones that popcornivores.
*sigh*
“…that are popcornivores.”
Too much looking at the Martian sun did it.
Since the world got warmer, they all had to diet in order to look good in swimwear.
This kind of attention grabbing publicity stunt discredits the value of any science these and other authors publish. I see no other reason for making press release statements that are substantiated by the research itself. That is not science. It is sophistry.
Garbage science. What we are witnessing is other disciplines trying to “prime the CAGW pump” for research dollars and publications.
Of course, it only works if you peg your paper to climate change, CO2 levels etc. How convenient to ignore the evolutionary drivers mentioned thus far by other posters.
Interesting that the hockey stick crowd are leaving the statistics journals alone! My hunch is that mathematical/statistical analysis of CAGW science by investigators such as McShane & Wyner will increase in the near future.
Well undoubtedly the high CO2 levels were due to our ancient ancestors driving SUVs
50 million years ago. 🙂
More seriously, when an article contains so many unknowns it would be better to just say “Um we don’t know”, and that would be much closer to the truth.
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.
Mammalian biologists have understood that the smaller size was do to the necessity of navigating the dense vegetation that replaced tundra plus a minor factor of thermodynamics, causing cold adapted animals tending to being of a larger size to conserve heat.
When Huxley and Orwell gave form to their dystopian visions they assumed that the future of humanity would be shaped by malevolent intelligence; I read items like this which emanate from our national seats of learning and realise that they never for a moment anticipated the real shaping force: low level immorality and stupidity. How did science get like this?
Okay, let’s review what we have learned here:
1. CO2 is very good for all living things.
2. More O2 and plentiful food may lead to bigger critters.
3. Big things stay warmer due to less surface/mass ratio.
4. Small things (like a 2 yr old) are more energetic (which explains why they can run in circles around the kitchen table squealing for 6 hrs straight)
One element of craziness is the idea that big animals are better adapted. If it was the case, elephant and whale would not be on the endangered list and rat would. So even if it was proven that Co2 is linked with smaller mammals, it would not mean it is bad. In fact, the opposite could be true. A warmer planet with more Co2 could make life easier. So mammals don’t need to be as big to survive. And it is known that smaller mammals mature faster so more generation can live in the same period of time. More generations means a faster evolution. There is so much more than size.