(Press-News.org) Evolving to become less aggressive could be key to saving the Tasmanian devil – famed for its ferocity – from extinction, research suggests. The species is being wiped out by Devil Facial Tumour Disease (DFTD), a fatal infectious cancer spread by biting. The new study, published in the British Ecological Society's Journal of Animal Ecology, found the less often a devil gets bitten, the more likely it is to become infected with the cancer.
According to lead author Dr Rodrigo Hamede of the University of Tasmania: "Our results – that devils with fewer bites are more likely to develop DFTD – were very surprising and counter-intuitive. In most infectious diseases there are so-called super-spreaders, a few individuals responsible for most of the transmission. But we found the more aggressive devils, rather than being super-spreaders, are super-receivers."
To find out whether biting frequency predicted acquiring DFTD, Dr Hamede and his colleagues set up dozens of devil traps at two sites for 10-day periods every three months between 2006 and 2010. They then recorded the pattern of injuries in the devils, and identified any tumours. One of the sites – West Pencil Pine – was selected because devils there seem to be less badly hit by the disease.
They made three discoveries: the level of bites was similar at both sites; devils with fewer bites were significantly more likely to develop DFTD; and most tumours occurred in devils' mouths. "This means that more aggressive devils do not get bitten as often, but they bite the tumours of the less aggressive devils and become infected," explains Dr Hamede.
Because there is no treatment for, or vaccine against, DFTD, the findings and the next stage of the research have important implications for saving the species from extinction. "Our next step is fascinating. First we need to explore the genetic differences that might be lessening the impact of DFTD in the West Pencil Pine devil population. Second, we need more detailed data on devil behaviour to define 'shy' or 'bold' types. We could then use this information to develop a management strategy to reduce the spread of the disease by boosting natural selection of less aggressive, and therefore more resilient, devils."
Understanding how infectious diseases spread is key to controlling them, but studying disease transmission in wild animals is often very difficult. And in DFTD, which is spread by biting, ecologists also need a better understanding of devil behaviour. Devils are solitary yet social animals. They do not live in groups but meet each other often, either during mating, establishing social hierarchies or when feeding around carcasses - all occasions when they bite each other.
###
Rodrigo K. Hamede, Hamish McCallum and Menna Jones (2012). 'Biting injuries and transmission of Tasmanian devil facial tumour disease', doi: 10.1111/j.1365-2656.2012.02025.x, is published in the Journal of Animal Ecology at 21:00 GMT on Monday 3 September 2012. END
Less ferocious Tasmanian devils could help save species from extinction
2012-09-05
ELSE PRESS RELEASES FROM THIS DATE:
Healing cuts for Medicare
2012-09-05
Medicare payment reforms mandated in the Affordable Care Act (ACA) for postacute care have great potential to lower costs without harming patients, a new study reports.
However, researchers caution, policymakers will need to be vigilant to ensure that these cuts don't result in one-time savings that revert to rising costs.
"We expect that the Affordable Care Act's dramatic cuts in payments to providers for postacute care will lead to decreased utilization and lower spending," said David Grabowski, Harvard Medical School professor of health care policy and lead author ...
National survey of economists uncovers vast gender gap in policy views
2012-09-05
Is there a "gender gap" in the views of professional economists? A new national study finds that while most economists agree on core economic concepts, values and methods, they differ along gender lines in their views on important economic policy.
The study – believed to be the first systematic analysis of male and female economists' views on a wide variety of policy issues – surveyed hundreds of members of the American Economic Association. The research team found that despite having similar training and adherence to core economic principles and methodology, male and ...
Birth of a planet
2012-09-05
The Earth and the planets of our solar system are not alone in the universe. Over the past few decades, the hunt for extrasolar planets has yielded incredible discoveries, and now planetary researchers have a new tool—simulated models of how planets are born.
Most planets form when a molecular cloud collapses into a young star. The leftover gas and dust form a disk around the star, and the particulates inside the disk begin to collide and coalesce over millions of years, forming larger and larger objects until a planet eventually takes shape.
Sally Dodson Robinson, ...
Magazines jeopardize and empower young women's sexuality
2012-09-05
Los Angeles, CA (September 4, 2012) While the effects of sexualized media on young women has long been debated, a new study finds that women who read sex-related magazine articles from popular women's magazines like Cosmopolitan are less likely to view premarital sex as a risky behavior. Additionally, the women who are exposed to these articles are more supportive of sexual behavior that both empowers women and prioritizes their own sexual pleasure. This study was published in a recent article from Psychology of Women Quarterly (published by SAGE).
Study authors Janna ...
Gardener's delight offers glimpse into the evolution of flowering plants
2012-09-05
The Pink Double Dandy peony, the Double Peppermint petunia, the Doubled Strawberry Vanilla lily and nearly all roses are varieties cultivated for their double flowers.
The blossoms of these and other such plants are lush with extra petals in place of the parts of the flower needed for sexual reproduction and seed production, meaning double flowers – though beautiful – are mutants and usually sterile.
The genetic interruption that causes that mutation helped scientists in the 1990s pinpoint the genes responsible for normal development of sexual organs stamens and carpels ...
Pretreatment PET/CT imaging of lymph nodes predicts recurrence in breast cancer patients
2012-09-05
Disease-free survival for invasive ductal breast cancer (IDC) patients may be easier to predict with the help of F-18-fludeoxyglucose positron emission tomography (PET)/computed tomography (CT) scans, according to research published in the September issue of The Journal of Nuclear Medicine. New data show that high maximum standard uptake value (SUVmax) of F-18-FDG in the lymph nodes prior to treatment could be an independent indicator of disease recurrence.
"Many studies have revealed that breast cancer patients with axillary lymph node metastasis have a significantly ...
Realizing the promise of RNA nanotechnology for new drug development
2012-09-05
New Rochelle, NY, September 4, 2012—The use of RNA in nanotechnology applications is highly promising for many applications, including the development of new therapeutic compounds. Key technical challenges remain, though, and the challenges and opportunities associated with the use of RNA molecules in nanotechnology approaches are presented in a review article in Nucleic Acid Therapeutics, a peer-reviewed journal from Mary Ann Liebert, Inc. The article is available free online at the Nucleic Acid Therapeutics website.
Peixuan Guo and colleagues, University of Kentucky, ...
Waste not, power up
2012-09-05
HOUSTON – (Sept. 4, 2012) – Researchers at Rice University and the Université catholique de Louvain, Belgium, have developed a way to make flexible components for rechargeable lithium-ion (LI) batteries from discarded silicon.
The Rice lab of materials scientist Pulickel Ajayan created forests of nanowires from high-value but hard-to-recycle silicon. Silicon absorbs 10 times more lithium than the carbon commonly used in LI batteries, but because it expands and contracts as it charges and discharges, it breaks down quickly.
The Ajayan lab reports this week in the journal ...
UCF researchers record world record laser pulse
2012-09-05
A University of Central Florida research team has created the world's shortest laser pulse and in the process may have given scientists a new tool to watch quantum mechanics in action – something that has been hidden from view until now.
UCF Professor Zenghu Chang from the Department of Physics and the College of Optics and Photonics, led the effort that generated a 67-attosecond pulse of extreme ultraviolet light. The results of his research are published online under Early Posting in the journal Optics Letters.
An attosecond is an incomprehensible quintillionith ...
Human impact felt on Black Sea long before industrial era
2012-09-05
When WHOI geologist Liviu Giosan first reconstructed the history of how the Danube River built its delta, he was presented with a puzzle.
In the delta's early stages of development, the river deposited its sediment within a protected bay. As the delta expanded onto the Black Sea shelf in the late Holocene and was exposed to greater waves and currents, rather than seeing the decline in sediment storage that he expected, Giosan found the opposite. The delta continued to grow. In fact, it has tripled its storage rate.
If an increase in river runoff was responsible for ...