Navigation Links
Earliest Known Horse Shrank Due to Warming Planet: Report
Date:2/23/2012

THURSDAY, Feb. 23 (HealthDay News) -- Rising global temperatures appear to have caused the earliest known horse to shrink in size, new research indicates.

When Sifrhippus first appeared in the forests of North America more than 50 million years ago, it weighed about 12 pounds.

The horse lived during the 175,000-year period of time called the Paleocene-Eocene Thermal Maximum, during which average global temperatures rose by about 10 degrees Fahrenheit. This temperature increase was caused by the release of huge amounts of carbon into the atmosphere and oceans.

During this period of global warming, about one-third of mammal species experienced significant reductions in size, researchers have found.

Fossilized teeth show that Sifrhippus shrank from about 12 pounds to about 8.5 pounds (a 30 percent reduction) during the first 130,000 years of the time period and then rebounded to about 15 pounds in the final 45,000 years of that era.

The findings offer new evidence of the cause-and-effect relationship between temperature and body size, and also offer clues to how animals might be affected by rising global temperatures in the near future, according to study leaders 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.

In the study, published in the Feb. 24 issue of the journal Science, the scientists performed an analysis of the oxygen isotopes in the fossilized teeth of Sifrhippus.

The results were "absolutely startling," according to Bloch. "We looked at the curve and we realized that it was exactly the same pattern that we were seeing with the horse body size."

He explained that for the first 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," Bloch said in a University of Nebraska-Lincoln news release.

Secord added: "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."

Scientists studying birds have already started to notice a possible decrease in birds' body size, Secord noted in the news release.

"One of the issues here is that warming [during the Paleocene-Eocene Thermal Maximum] 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?"

More information

The Florida Museum of Natural History offers a fossil horse cybermuseum.

-- Robert Preidt

SOURCE: University of Nebraska-Lincoln, news release, Feb. 23, 2012


'/>"/>
Copyright©2010 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. NIH scientists find earliest known evidence of 1918 influenza pandemic
2. Ancient Footprints Reveal Earliest Signs of Human-Like Gait
3. Gene expression changes in nasal cells may help identify lung cancer in earliest stages
4. Young Children Can Access Earliest Memories, Study Finds
5. New induced stem cells may unmask cancer at earliest stage
6. UCSF Transgenic Mouse Mimics Parkinson's Earliest Symptoms
7. Autisms earliest symptoms not evident in children under 6 months
8. New combo of chemo and well-known malaria drug delivers double punch to tumors
9. Oldest Known Dinosaur Nesting Site Found
10. More Known About Proteins That Cause Autoimmune Diseases
11. Little Known About How Autism Affects Teen Drivers: Researchers
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Earliest Known Horse Shrank Due to Warming Planet: Report
(Date:8/18/2017)... ... 2017 , ... Hernandez Insurance Agencies, a northern Virginia firm ... DC region, is inaugurating a “New Leash On Life” charity initiative in conjunction ... to be companions for veterans in need. , The Semper K9 organization works ...
(Date:8/18/2017)... ... August 18, 2017 , ... MLM Insurance Group, a ... throughout southern Florida, is working to support the Take Stock In Children Foundation ... income families. , The Take Stock In Children Foundation (TSC) offers guidance and ...
(Date:8/18/2017)... ... 2017 , ... The Golseth Agency, a Texas based insurance management and financial ... regional charity campaign organized to provide support to Christina Upchurch and her two children ... and her children returned from out of town to find her husband passed away ...
(Date:8/18/2017)... ... 18, 2017 , ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh in Abilene, ... on false teachings pertaining to the mother of the Savior whom the world calls “Mother ... different picture of the role of this historical woman. , “The world bows, kisses ...
(Date:8/18/2017)... ... August 18, 2017 , ... 800response, the leading ... solutions, announced today the launch of a redesigned corporate website, 800response.com . ... fully responsive design, and an enhanced search directory for businesses and advertising agencies ...
Breaking Medicine News(10 mins):
(Date:8/15/2017)... Inc., the creator of the drug Truveta for the treatment ... IPO. The United States spends approximately ... prescription epilepsy drug being $450.00-$1200.00 for a one month supply. ... AXIUM PHARMACEUTICALS, INC ... is the fact that Americans spent $42 billion on anxiety medications last ...
(Date:8/14/2017)... HACKENSACK, N.J. and PETACH TIKVAH, ... Therapeutics Inc. (NASDAQ: BCLI), a leading developer of adult ... for the second quarter ending June 30, 2017. ... advanced stages of preparing for our pivotal Phase 3 ... Chaim Lebovits , President and Chief Executive Officer ...
(Date:8/8/2017)...  BioLineRx Ltd. (NASDAQ/TASE: BLRX), a clinical-stage biopharmaceutical company ... results for the second quarter ended June 30, 2017. ... 2017 and to date: ... the Company,s lead project, BL-8040: Announced ... as novel stem cell mobilization treatment for autologous bone-marrow ...
Breaking Medicine Technology: