An illustration of the earliest-known horse, Sifrhippus, dwarfed next to a modern domestic horse. Courtesy of Danielle Byerley, Florida Museum of Natural History
Posted on 03/02/2012 9:03:13 AM PST by null and void
An illustration of the earliest-known horse, Sifrhippus, dwarfed next to a modern domestic horse. Courtesy of Danielle Byerley, Florida Museum of Natural History
As scientists continue developing climate change projection models, paleontologists studying an extreme short-term global warming event have discovered direct evidence about how mammals respond to rising temperatures. In a study appearing in Science February 24, 2012, researchers from eight institutions, led by scientists from the University of Florida and University of Nebraska, found a correlation between temperature and body size in mammals by following the evolution of the earliest horses about 56 million years ago: As temperatures increased, their body size decreased.
“Horses started out small, about the size of a small dog like a miniature schnauzer,” said co-author Jonathan Bloch, associate curator of vertebrate paleontology at the Florida Museum of Natural History on the UF campus. “What’s surprising is that, after they first appeared, they then became even smaller and then dramatically increased in size, and that exactly corresponds to the global warming event, followed by cooling. It had been known that mammals were small during that time and that it was warm, but we hadn’t understood that temperature specifically was driving the evolution of body size.”
Sifrhippus, the earliest-known horse, first appeared in the North American fossil record during the Paleocene-Eocene Thermal Maximum. During this 175,000-year climate event, increased concentrations of carbon dioxide in the atmosphere and oceans caused average global temperatures to rise 10 to 20 degrees. By analyzing the size and isotopes of fossils collected in Wyoming’s Bighorn Basin, researchers traced the evolution of Sifrhippus from an estimated 12-pound animal that shrank during a 130,000-year period by about 30 percent to 8.5 pounds — the size of a small house cat — then increased to about 15 pounds during the next 45,000 years.
“This is the highest-resolution terrestrial record of its kind from anywhere in the world, and it shows how climate changed in Wyoming at that time,” said lead author Ross Secord, who began geochemical analysis of the horse teeth and other mammals as a postdoctoral researcher with Bloch before joining the University of Nebraska-Lincoln in 2008. “When Jon and I started plotting oxygen data from the mass spectrometer, we could immediately see that the shifts in size of horses and temperature were mirror images of each other.”
Bloch said the project began about seven years ago when former UF student and study co-author Stephen Chester, now an anthropology doctoral candidate at Yale University, measured horse teeth that seemed to be too large for their age and became smaller through the geologic section. The findings raise important questions about how animals might respond to future rapid climate change.
“We’re seeing about a third of the mammals getting smaller, and some of them getting a lot smaller, by as much as half of their original body size,” Secord said. “Because warming happened much slower during the Paleocene-Eocene Thermal Maximum, mammals had more time to adjust their body size. So, it’s not clear that we’re going to see the same thing happening in the near future, but we might.”
Philip Gingerich, who first recorded the phenomenon of decreasing body size during the Paleocene-Eocene Thermal Maximum in 1989, said the study documentation clearly demonstrates the relationship between temperature and body size. He agrees this may occur as a result of current warming patterns.
“I joke about this all the time — we’re going to be walking around three feet tall if we keep going the way we’re going,” said Gingerich, a researcher at the University of Michigan and director of its Museum of Paleontology. “Maybe that’s not all bad and, if that’s the worst it gets, it will be fine. You can either adapt, or you go extinct, or you can move, and there’s not a lot of place to move anymore, so I think it’s a matter of adaptation and becoming smaller.”
Researchers also analyzed correlations with aridity and carbon dioxide levels, but found temperature to be the most likely driving factor in body size. Although little is known about how animals arrived in North America at that time, the Paleocene-Eocene Thermal Maximum (PETM) is a significant event in geologic time in terms of mammalian history, Bloch said.
“The PETM is really important, because it marks the beginning for the first appearance of several major groups of mammals, including crown-group primates (ancestors of modern primates) and the first even- and odd-toed modern ungulates (mammals with hooves),” Bloch said. “This sets the scene for the entire diversity of animals we see on the planet today.”
Study co-authors include Doug Boyer of Brooklyn College, Aaron Wood of South Dakota School of Mines and Technology and the Florida Museum, Scott Wing of the Smithsonian Institution National Museum of Natural History, Mary Kraus of the University of Colorado, Francesca McInerney of Northwestern University and John Krigbaum of UF.
Sounds like a typical place for a liberal to start...
” Massive Carbon Release Shrinks Horses to Size of House Cats”
On the plus side, cats were enlarged to the size of houses.
Of course, houses were somewhat smaller then, about the size of an artificially enlarged doormouse, or a shriveled Cheshire cat.
Thieves in Florida can walk right under your locked door. Of course, all they can steal is a lint ball.
We (meaning all us humans) were quite a bit smaller if you go back 200-300 years. Look at the below-decks space on sailing ships, or the average size of armor, or clothes, or beds.
So it is possible for our size to me “modulated” by circumstance. better food distribution, pesticides, heated buildings, awareness of nutrition factors, medicine, and broadened interbreeding all conspired to make us bigger. Maybe 500 years from now we’ll be bigger yet, or smaller 9see, like global warming’ I’ll cover all of the bases), or maybe the same size.
Aw shucks!
That would have been a horse I could afford to keep.
I've always wanted to belong to the equestrian class.
However, many other things affect size. For example, there's the "island effect" which causes Indonesian hippos, rhinos, and elephants (and perhaps even humans such as the Flores Hobbit man) to be much smaller than their African relatives. Changing food supplies and introduction of new species also affect size.
Therefore, for these scientists to say that global warming caused this one type of animal to shrink is really stretching for a reason.
Easy, globull warming causes everything from acne to cold weather to earthquakes.
How do they know which is the cause and which is the effect?
PATENT BULLSHIT!!
“That would have been a horse I could afford to keep. “
Easier to herd than cats, too, I bet.
Therefore larger horses means a greater volume of horse flatulence; ergo, increased global warming!
Hard to believe what passes as science today...
Not very long ago....this article would be considered written by a crackpot...
How much did this cost the taxpayers
Not only don't they know which is the cause and which is the effect, they do NOT know if there is a cause and an effect. That is why these "global warming" "scientists" are not scientists. They mistake correlation for causality.
Here is an example of their illogic:
98 percent of Americans involved in traffic accidents had eaten potatoes within 24 hours of the accident. The conclusions of those nitwits would be:
(1) Consuming potatoes causes traffic accidents.
Banning the consumption of potatoes will save billions in damage to automobiles and about 41,000 American lives on the roads each year.
You end up with nonsense like this when the schools stop teaching scientific principles and methods and start teaching the religion of Al Gorism.
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