(Press-News.org) Turtles are more closely related to birds and crocodilians than to lizards and snakes, according to a study from Dartmouth, Yale and other institutions that examines one of the most contentious questions in evolutionary biology.
The findings appear in the journal Evolution & Development. A PDF of the study is available on request.
The research team looked at how the major groups of living reptiles, which number more than 20,000 species, are interrelated. The relationships of some reptile groups are well understood -- birds are most closely related to crocodilians among living reptiles, while snakes, lizards and New Zealand's tuatara form a natural group. But the question of how turtles fit into this evolutionary picture has remained unclear. Are turtles more closely related to archosaurs (birds and crocodilians) or to lepidosaurs (lizards, snakes and tuatara)? Or are these other reptiles more closely related to each other than to turtles?
A growing number of studies examining DNA sequences have suggested a close evolutionary kinship between turtles and archosaurs, but those results were contradicted by anatomical studies and a recent study of small biomolecules called microRNAs. Because microRNAs are viewed by some as excellent evolutionary markers, the conflict between the microRNA and DNA results meant the turtle-archosaur link was viewed skeptically by many.
But the Dartmouth-led team's research suggests the earlier microRNA conclusions were erroneous, and instead indicates that microRNAs and DNA sequences yield a common signal -- that turtles share a more recent common ancestor with birds and crocodilians than with lizards and snakes.
INFORMATION:
The study included researchers from Dartmouth, Yale, the Smithsonian Institution, Mount Desert Island Biological Research Station and University of Bristol. Support came from the Yale Peabody Museum, Government of Alberta, Canadian Natural Sciences and Engineering Research Council and NASA.
Available to comment are senior author Dartmouth Professor Kevin Peterson at Kevin.J.Peterson@dartmouth.edu and lead author Daniel Field, a Yale graduate student and a predoctoral fellow at the Smithsonian Institution's National Museum of Natural History, at daniel.field@yale.edu
Broadcast studios: Dartmouth has TV and radio studios available for interviews. For more information, visit: http://www.dartmouth.edu/~opa/radio-tv-studios/
Tracking turtles through time, Dartmouth-led study may resolve evolutionary debate
2014-05-05
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Climate change threatens to worsen US ozone pollution
2014-05-05
BOULDER -- Ozone pollution across the continental United States will become far more difficult to keep in check as temperatures rise, according to new research led by the National Center for Atmospheric Research (NCAR). The detailed study shows that Americans face the risk of a 70 percent increase in unhealthy summertime ozone levels by 2050.
This is because warmer temperatures and other changes in the atmosphere related to a changing climate, including higher atmospheric levels of methane, spur chemical reactions that lead to ozone.
Unless emissions of specific pollutants ...
Genetic, environmental influences equally important risk for autism spectrum disorder
2014-05-05
In the largest family study on autism spectrum disorder (ASD) to date, researchers from the Icahn School of Medicine at Mount Sinai, along with a research team from the Karolinska Institutet in Stockholm Sweden and King's College in London found that individual risk of ASD and autistic disorder increased with greater genetic relatedness in families – that is, persons with a sibling, half-sibling or cousin diagnosed with autism have an increased likelihood of developing ASD themselves. Furthermore, the research findings showed that "environmental" factors unique to the ...
Energy-subsidy reform can be achieved with proper preparation, outside pressure
2014-05-05
HOUSTON – (May 5, 2014) – Reform of energy subsidies in oil-exporting countries can reduce carbon emissions and add years to oil exports, according to a new paper from Rice University's Baker Institute for Public Policy.
"Navigating the Perils of Energy-Subsidy Reform in Exporting Countries" was authored by Jim Krane, the Wallace S. Wilson Fellow for Energy Studies at the Baker Institute, who specializes in energy geopolitics. The paper reviews the record of energy-subsidy reforms and argues that big exporters should reduce energy demand by raising prices, and that this ...
Liver cancer screening highly beneficial for people with cirrhosis
2014-05-05
DALLAS – May 5, 2014 – Liver cancer survival rates could be improved if more people with cirrhosis are screened for tumors using inexpensive ultrasound scans and blood tests, according to a review by doctors at UT Southwestern Medical Center.
The meta-analysis of 47 studies involving more than 15,000 patients found that the three-year survival rate was much higher among patients who received liver cancer screening— 51 percent for patients who were screened compared to 28 percent of unscreened patients. The review also found that cirrhosis patients who were screened for ...
Study finds family-based exposure therapy effective treatment for young children with OCD
2014-05-05
PROVIDENCE, R.I. – A new study from the Bradley Hasbro Children's Research Center has found that family-based cognitive behavioral therapy (CBT) is beneficial to young children between the ages of five and eight with Obsessive-Compulsive Disorder (OCD). The study, now published online in JAMA Psychiatry, found developmentally sensitive family-based CBT that included exposure/response prevention (EX/RP) was more effective in reducing OCD symptoms and functional impairment in this age group than a similarly structured relaxation program.
Jennifer Freeman, Ph.D., a staff ...
Tomato turf wars: Benign bug bests salmonella; tomato eaters win
2014-05-05
Scientists from the U.S. Food and Drug Administration (FDA) have identified a benign bacterium that shows promise in blocking Salmonella from colonizing raw tomatoes. Their research is published ahead of print in the journal Applied and Environmental Microbiology.
When applied to Salmonella-contaminated tomato plants in a field study, the bacterium, known as Paenibacillus alvei, significantly reduced the concentration of the pathogen compared to controls.
Outbreaks of Salmonella traced to raw tomatoes have sickened nearly 2,000 people in the US from 2000-2010, killing ...
Physician practice facilitation ensures key medical care reaches children
2014-05-05
Leona Cuttler, MD, knew in her core that the simple act of adding an outside eye could dramatically improve pediatric care.
Today, a study of more than 16,000 patient visits published online in the journal Pediatrics proves Cuttler's thesis correct. The lead investigator on the research project, Cuttler succumbed to cancer late last year. But her colleagues are committed to seeing its lessons disseminated across the country.
"It was an honor to work on this project with Dr. Cuttler," said study first author Sharon B. Meropol, MD, PhD, Assistant Professor, Departments ...
ORNL paper examines clues for superconductivity in an iron-based material
2014-05-05
OAK RIDGE, Tenn., May 5, 2014 – For the first time, scientists have a clearer understanding of how to control the appearance of a superconducting phase in a material, adding crucial fundamental knowledge and perhaps setting the stage for advances in the field of superconductivity.
The paper, published in Physical Review Letters, focuses on a calcium-iron-arsenide single crystal, which has structural, thermodynamic and transport properties that can be varied through carefully controlled synthesis, similar to the application of pressure. To make this discovery, researchers ...
New cause of high blood pressure and heart disease discovered
2014-05-05
Phosphate rich foods include processed cheese, Parmesan, cola, baking powder and most processed foods. Phosphates are widely used in the food industry as preservatives and pH stabilizers. When large quantities of phosphates are consumed, production of the FGF23 hormone is stimulated, which has a negative effect on the cardiovascular system. Reinhold Erben, the head of the Unit of Physiology, Pathophysiology and Biophysics at the Vetmeduni Vienna, warns that "our phosphate consumption is relevant for our state of health."
Over 500 million people around the world suffer ...
No credible evidence to support cardiac risk of testosterone therapy
2014-05-05
New Rochelle, NY, May 5, 2014—Recent articles in the scientific literature and mass media that question the use of testosterone (T) therapy to treat T deficiency, or "low T," and assert the cardiovascular risks of T therapy, are flawed, according to a provocative Guest Editorial in Journal of Men's Health, a peer-reviewed publication from Mary Ann Liebert, Inc., publishers. The article is available free on the Journal of Men's Health website at http://www.liebertpub.com/jmh.
In "Testosterone Therapy and Cardiovascular Risk: A Cautionary Tale" Martin Miner, MD, The Warren ...