From the University of Nebraska-Lincoln . Tom Nelson quipped earlier today that he hadn’t noticed any pygmy horses near the equator where it is warmer.
Study: Evolution of earliest horses driven by climate change
New research offers evidence of rising temperatures’ effects on body size
When Sifrhippus, the earliest known horse, first appeared in the forests of North America more than 50 million years ago, it would not have been mistaken for a Clydesdale. It weighed in at around 12 pounds — and it was destined to get much smaller over the ensuing millennia.
Sifrhippus lived during the Paleocene-Eocene Thermal Maximum, a 175,000-year interval of time some 56 million years ago in which average global temperatures rose by about 10 degrees Fahrenheit, caused by the release of vast amounts of carbon into the atmosphere and oceans.
About a third of mammal species responded with significant reduction in size during the PETM, some by as much as one-half. Sifrhippus shrank by about 30 percent to the size of a small house cat (about 8.5 pounds) in the PETM’s first 130,000 years and then rebounded to about 15 pounds in the final 45,000 years of the PETM.
Scientists have assumed that rising temperatures or high concentrations of carbon dioxide primarily caused the phenomenon in mammals during this period, and new research led by Ross Secord of the University of Nebraska-Lincoln and Jonathan Bloch of the Florida Museum of Natural History at the University of Florida in Gainesville offers new evidence of the cause-and-effect relationship between temperature and body size. Their findings also offer clues to what might happen to animals in the near future from global warming.
In a paper to be published in the Feb. 24 issue of the international journal Science, Secord, Bloch and colleagues used measurements and geochemical composition of fossil mammal teeth to document a progressive decrease in Sifrhippus‘ body size that correlates very closely to temperature change over a 130,000-year span.
Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History, said multiple trails led to the discovery.
One was the fossils themselves, recovered from the Cabin Fork area of the southern Bighorn Basin near Worland, Wyo. Stephen Chester, then an undergraduate student at Florida, now an anthropology Ph.D. candidate at Yale and a co-author on the paper, had the task of measuring the horses’ teeth. What he found when he plotted them through time caught Bloch and Secord by surprise.
“He pointed out that the first horses in the section were much larger than those later on,” Bloch recalled. “I thought something had to be wrong, but he was right — and the pattern became more robust as we collected more fossils.”
A postdoctoral researcher in Bloch’s lab for the first year of the project, Secord performed the geochemical analysis of the oxygen isotopes in the teeth. What he found provided an even bigger surprise.
“It was absolutely startling when Ross pulled up the first oxygen isotope data,” Bloch said. “We looked at the curve and we realized that it was exactly the same pattern that we were seeing with the horse body size.
“For the first time, going back into deep time — going back tens of millions of years — we were able to show that indeed temperature was causing essentially a one-to-one shift in body size within this lineage of horse. Because it’s over a long enough time, you can argue very strongly that what you’re looking at is natural selection and evolution — that it’s actually corresponding to the shift in temperature and driving the evolution of these horses.”
Secord, who came to UNL in 2008 as an assistant professor of Earth and atmospheric sciences and curator of vertebrate paleontology at the University of Nebraska State Museum, said the finding raises important questions about how plants and animals will respond to rapid change in the not-too-distant future.
“This has implications, potentially, for what we might expect to see over the next century or two, at least with some of the climate models that are predicting that we will see warming of as much as 4 degrees Centigrade (7 degrees Fahrenheit) over the next 100 years,” he said.
Those predictions are based largely on the 40 percent increase of atmospheric carbon dioxide levels (from 280 to 392 parts per million) since the start of the Industrial Revolution in the mid-19th century.
Ornithologists, Secord said, have already started to notice that there may be a decrease in body size among birds.
“One of the issues here is that warming (during the PETM) happened much slower, over 10,000 to 20,000 years to get 10 degrees hotter, whereas now we’re expecting it to happen over a century or two,” Secord said. “So there’s a big difference in scale and one of the questions is, ‘Are we going to see the same kind of response?’ Are animals going to be able to keep up and readjust their body sizes over the next couple of centuries?”
Increased temperatures are not the only change animals will have to adapt to, Secord said. Greenhouse experiments show that increased atmospheric carbon dioxide lowers the nutritional content of plants, which he said could have been a secondary driver of dwarfism during the PETM.
Other co-authors on the paper are Doug M. Boyer of Brooklyn College, Aaron R. Wood of the Florida Museum of Natural History, Scott L. Wing of the Smithsonian National Museum of Natural History, Mary J. Kraus of the University of Colorado-Boulder, Francesca A. McInerny of Northwestern University, and John Krigbaum of the University of Florida.
The research was funded by grants from the National Science Foundation, with additional support from UNL.
Did we learn now that CAGW will lead straight to dwarfism?
This would mean 1 hamburger could feed 2 people, one bathtub full would suffice for 2?
This is how we can save resources…half the bills, half the gas, the airplains will carry
twice the people in one flight…..
Who says CAGW is terrible? Humans will/can adapt ……
Its an Warmist lie that the penguins will be the real survivors on Earth, “because they
can breed on the idle rocks of the Antarktis holding teir eggs between the legs…”
Mankind will not die out but adapt, and this is the good news….
JS
Toto says:
February 23, 2012 at 8:39 pm
Can we call this the “Myth of Sifrhippus”?
Easy for you to say.
Indeed, it would have been hard to see such prey, inasmuch as it evolved 15 or 20 million years after the extinction of the Rex. Unless it had tachyon-sensitive eyeballs.
“Their findings also offer clues to what might happen to animals in the near future from global warming.”
Too late, here in Hong Long, I’ve got a couple of Asian elephants curled up at the foot of my bed. They’re pink.
Now wait just a darn minute. Decades ago scientists were saying that in a COLD world, things get smaller, including humans. I remember seeing a drawing in I think National Geographic, that depicted what a human would look like in the next ice age and they were short. Like me.
Is this another one of those, “If things get smaller the world is warming. And if things get smaller the world is cooling. And its all our fault.”?
So hot climates lead to tiny animals. That’s why there are no large mammals in Africa, India, South East Asia, or South America.
Elephants, Giraffes, Tigers, Lions, Hippos, Tapirs, Jaguars, Capybara, Gorillas, Rhinos, Orangutans, Water Buffaloes, etc, etc. all live on the praries of Alberta or in the mighty forests of British Columbia.
Thank goodness for heat-related dwarfism. Otherwise, T. Rex would have been 5000 feet long, and weighed more than 100 blue whales! He would have swallowed the Chuxulub meteorite and belched, and then set out to munch everything that otherwise evolved to produce us humans. We caught a break, folks.
So people who work in greenhouses (where CO2 is elevated to several thousand ppmv to promote plant growth) can expect to get smaller?
Maybe those who are overweight (or tired of having to find Big and Tall shops) should be preferentially selected for greenhouse jobs.
On the other hand, I’m shrinking with age, so should I get a CO2 collector and hope to regain my height from an atmosphere devoid of that gas?
So many questions–so few answers.
I keep reading that this or that will happen because of global warming. What bloody global warming are these fools talking about? Does any reporter actually ask the so called scientists about the amount of global warming they are speculating on? Idiots.
I think Pochas was being facetious. How about crocodiles?
http://ngm.nationalgeographic.com/2011/10/hothouse-earth/block-photography#/05-bighorn-oxidized-soil-670.jpg
Oh! I can see it now. As CO2 rises and temperatures soar, we humans are all going to shrink to the size of Leprechauns. We won’t be able to reach up to the doorknobs and the light switches. We will all be trapped indoors watching television in the dark for eternity.
What an unrivalled, unrelieved load of twaddle sponsored by the University of Nebraska in Lincoln.
Crispin in Waterloo says:
February 23, 2012 at 5:35 pm
What will happen? Probably the same thing that happened when 3 ices ages saw the temperature go up and down even more dramatically that during ther 130,000 years: nothing.
Niot quite true. There is a general tendency that animals grow slightly larger during ice ages and smaller during interglacials. This has been known for close on 200 years. For details google “Bergmanns rule”.
I presume they have some proof from these teeth that the CO2 rise preceded the temperature rise by a few years, not followed it by 800 as happens the rest of the time.
There is no reliable way of measuring CO2 over short periods that far back, and as far as I know nobody has ever managed to measure it at all for the PETM (which is quite short geologically speaking). What can be measured with precision is the isotopic changes of carbon which are interpreted as being due to the release of massive amounts of organic carbon. For what it’s worth it does seem that temperature start rising slightly before the isotopes start shifting.
In any case there is nothing new in this. It was described in detail by Gingerich twenty years ago from the very same site (Polecat bench) (Gingerich, P.D., 1989, New earliest Wasatchian mammalian fauna from the Eocene of northwestern Wyoming: Composition and diversity in a rarely sampled high-floodplain assemblage: University of Michigan Papers on
Paleontology, v. 28, p. 1–97, available at: http://deepblue.lib.umich.edu/handle/2027.42/48628) and reviewed by him in 2003 as: Mammalian responses to climate change at the Paleocene-Eocene boundary: Polecat Bench record in the northern Bighorn Basin, Wyoming. Geological Society of America Special Paper 369. (available at:http://www-personal.umich.edu/~gingeric/PDFfiles/PDG402_Mammresppebound.pdf)
Notice that the title has been “sexed up” quite a bit between 1989 and 2003.
This is an excellent example of “press-release science”, a rehash of well-known facts as new “research” with a CAGW slant.
We know that 97% of climate scientists agree the sky is falling due to man made global warming but the good news is you don’t have to worry about the warming (or your head shrinking) anymore-
http://www.theage.com.au/environment/climate-change/falling-clouds-could-counter-global-warming-20120222-1tmpw.html#ixzz1nA5rIEJH
Just so long as you don’t mind your head being stuck in the clouds of course.
In the carboniferous CO2 levels went from something like 3000ppm to 300ppm over 100million years during which the coal seams were laid down. Note the word “seamS. It was not one big dump. It was repeated change in sea level. Whatcauses repeated changes in sea level? Glaciers. Anyway the interesting bit is that it was due to a new material in plants called lignin which it appears to have taken fungi a 100million years to work out how to decompose.
But the main point is that plant evolution can be a strong driver of atmospheric change.
So when some numb-skull says that horses responded to climate. What appears far more likely is that horse and climate responded to some change in plant or perhaps general evolution.
Now for years, I’ve been telling my kids that rabbits killed the dinosaurs. OK, that’s just fun, but in the time of the dinosaurs, there was no grass, after the time of the dinosaur there is grass. Grass is a habitat that exists because of grass grazers. Grass grazers have teeth that cut the grass low to the ground … which is alright for grass as it grows again from the root. However it is death for most other plants particularly trees which grow from the tip.
So a habitat of grass-“rabbit” i.e. small mammals, would evolve together as a very aggressive environment – and it is now virtually impossible to find any habitat in the world where there is not grass from under the sea to the highest mountain tops (in Scotland).
The point is that animal evolution is tied to plant evolution. And visa versa. And I suppose animals use bacteria to digest grass … so even changes to gut fauna could drive evolution. Perhaps either the grass changed to become more easily digested, or the bacteria fauna in the gut or …
But the real clincher is that paper that shows that local vegetative cover effects local climate. So, we already know type of vegetation is a driver of climate.
Now, if they had come up with some research explaining why Shetland ponies have unique hair that is extra long to sustain them in the cold. Or why pit ponies were smaller. Or why cart horses are so big. NOw that really would have been worth a grant .
So they shrank 30% in 130,000 years and scientists claim they have already detected to effect after 40 years? Seems there is some sort of logical disconnect .
Nevertheless, if it turns out to be a universal effect it holds out hope for the future of the human race, as presumably smaller people will consume less resources per capita and thus reduce the impact of overpopulation.
observa says: February 24, 2012 at 12:13 am
We know that 97% of climate scientists agree the sky is falling
The consensus of those who believe in a consensus is that there is a consensus amongst the consensus that the consensus is true. However there is also a consensus amongst those who do not believe in the consensus that a consensus amongst the consensus that the consensus is true is a con sent us .
“Greenhouse experiments show that increased atmospheric carbon dioxide lowers the nutritional content of plants”
The C/N ratio changes somewhat in the leaves, that means that you have more carbohydrates and less proteins, but in the seeds, the ratio remains largely the same. Because most herbivores eat a mix, the influence is minimal. Only for some caterpillars it may be important, but that are not horses…
For humans that doesn’t show up: both the tallest (Tutsi) and the smallest (pygmees) evolved in the hotter parts of the globe…
“Toto says:
February 23, 2012 at 8:39 pm
Can we call this the “Myth of Sifrhippus”?”
You could but I couldn’t! 😉
On one of my agw presentation slides I use a line “if it was an undergrad dissertation it would fail”. This ‘paper’ justifies that comment. If a dissertation was presented to me that started with “I’ve just assumed the main correlation” it would fail. How do they get away with it????
As I’ve said before, there’s a Zappa quote for just about any situation and pygmy ponies are no exception.
Montana
Here’s a thought.
Just recently when I’ve posted skeptical opinions on other blogs…I have been labelled a Denier and bundled with ‘Creationists’.
Gleick in his dreary film posted at the top of WUWT…reckons that with proper ‘education’
“we can do for climate change what we’ve done for Evolution.”
This seems to be a new Warmist smear tactic.
But isn’t it fascinating then that none of the people who have posted above, most of whom are AGW skeptics, appear to hold Creationist viewpoints?
Warmism really is clutching at straws now.
A very long time ago when I was a little boy I’ve been told that storks are delivering babies. Every fall they’ld fly to the big baby cradle to fetch new babies and bring them to us in spring or summer.
So you need a lot of storks to do that delivery service. As time went by stork’s population shrank and so did birth rates. When the stork population grew again there was a baby boom in our country. A perfect correlation and a good proof /irony.
Seems everyone has covered why this is crap science. Found one curious line I hadn’t heard before, perhaps political, to counter the increasing plant growth from CO2.
Greenhouse experiments show that increased atmospheric carbon dioxide lowers the nutritional content of plants, which he said could have been a secondary driver of dwarfism during the PETM.
http://www.adelaidenow.com.au/news/breaking-news/global-warming-shrank-horses-to-size-of-miniature-schnauzers-study-claims/story-e6frea73-1226280192006
as always any climate crap is NOT allowed comments there:-)
I spat and spun on reading it!
soooo assbackwards, and presented as experts talking so it has to be true.
I never cease to be amazed at how you CAN teach and promulgate Stupid! in whats supposed to be an enlightened society.
if this? is enlightened the bulbs burnt out!
Then how come Dinosaurs were that big in a time when CO2 was much higher for millions of years?
Quite a lot of evidence for what has been called “Cope’s law” I think. This is the observation that individuals tend to be larger in the northern (in the northern hemisphere) part of their ranges. China is a good case in point. Northern Chinese average much taller than southern Chinese. You can see the same thing in Europe, with Scandanavians taller than Italians. This makes good sense considering thermoregulation and surface area to body volume arguments. The same observation has been made for many mammal species.