(Press-News.org) It is often difficult to decide whether two animals belong to the same or two distinct species. This can be especially challenging for animals which externally look very similar. In a recent study, published in the open access journal Zoosystematics and Evolution, scientists from the Museum für Naturkunde Berlin use genetic data and sound analysis to test if treefrogs from West and Central Africa belong to different or the same species.
Due to the fact that, when external characters are used, only size is useful to distinguish these frogs the scientists employed additional characters to determine species affiliations. One the one hand, they used genetics, and, on the other, advertisement calls of different populations. Male frogs have to attract their females via species specific calls, so call characteristics (e.g. duration, frequency) reliably tell whether animals belong to one or several species.
The two sets of populations have been previously declared as belonging to the same species based on morphological, meaning external, similarities. With their work the researchers from Berlin proved their expectations right, and revealing they were in fact working with four and not two species: two different sets of one large and one small specie, which live in West and Central Africa respectively.
In order to facilitate other researchers the verification of these results, not only genetic but also acoustic data are publicly available and the latter can be downloaded from the animal sound archive of the Museum für Naturkunde.
Species are the basis for all biological questions. Therefore, they are not only important for taxonomists but also a reference parameter for physiologists, ecologists or conservationists. Thus it is of central importance to be able to distinguish whether animals of two different populations belong to one or two distinct species. A clear showcase is an example, which was examined in a recent publication by zoologist from Berlin and Geneva.
AUDIO:
This is audio of the "chuck " call of Leptopelis spiritusnoctis from Taï National Park, Ivory Coast. Files are also available from the Tierstimmenarchiv at the Museum für Naturkunde, Berlin: END
One or 2? How to decide how many species you have got
2014-04-02
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Remotely operated aircraft successfully tested as tool for measuring changes in polar ice sheets
2014-04-02
Scientists studying the behavior of the world's ice sheets--and the future implications of ice sheet behavior for global sea-level rise--may soon have a new airborne tool that will allow radar measurements that previously would have been prohibitively expensive or difficult to carry out with manned aircraft.
In a paper published in the March/ April edition of IEEE Geoscience and Remote Sensing Magazine, researchers at the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas noted that they have successfully tested the use of a compact radar system ...
Don't move a mussel (or a clam, or a snail)
2014-04-02
(Millbrook, NY) Anyone that has spent time at a seaside pier has witnessed the destruction barnacles wreak on boat hulls. But biofouling animals are not limited to marine environments. A new paper published in the journal Frontiers in Ecology and the Environment estimates that the global management of freshwater mussels, clams, and other clinging animals costs $277 million U.S. dollars annually.
Biofoulers are organisms that accumulate underwater on hard surfaces, to the detriment of property and economically important activities, such as shipping, power generation, ...
Beyond proficiency: How early English exposure influences non-native speakers
2014-04-02
PRINCETON, N.J.—Non-native speakers exposed to English before moving to America are more likely to use the language in their daily lives in the United States, according to a report led by Princeton University's Woodrow Wilson School of Public and International Affairs.
Such early exposure – through newspapers, books, TV and classes as well as traveling – may help determine an immigrant's socioeconomic mobility, as English proficiency is strongly tied to cultural and social assimilation. The report, featured in the journal Social Science Research, is one of the first ...
Americans using more energy according to Lawrence Livermore analysis
2014-04-02
Americans used more renewable, fossil and even nuclear energy in 2013, according to the most recent energy flow charts released by Lawrence Livermore National Laboratory.
Each year, the Laboratory releases energy flow charts that illustrate the nation's consumption and use of energy. Overall, Americans used 2.3 quadrillion thermal units more in 2013 than the previous year.
The Laboratory also has released a companion chart illustrating the nation's energy-related carbon dioxide emissions. Americans' carbon dioxide emissions increased to 5,390 million metric tons, ...
Killing a name of an extinct sea cow species
2014-04-02
Sirenians, or sea cows, are a particular group of mammals that superficially resembles whales in having, amongst other features, a streamlined-body and horizontal tail fluke. Though belonging to the so-called marine mammals, such as whales and seals, sea cows are members of a group having a single origin that includes their closest living relatives, the proboscideans (or elephants in the broader sense).
Today, sirenians are known by only four species, but their fossil record is much more diverse documenting the transition from land-dwelling animals to fully aquatic ones. ...
Ethics guidelines for next generation of risky NASA missions
2014-04-02
MEDIA ADVISORY: Institute of Medicine Committee to Report on Ethical Guidelines For Health Standards on Next Generation of NASA Missions: Long Duration and Exploration Spaceflights
WHEN: Embargoed until Wednesday April 2, 2014 11:00 AM EDT
WHAT: Spaceflights beyond low earth orbit or lasting longer than 30 days, including extended stays on the International Space Station and missions to Mars, will likely expose astronauts to increased and even unknown levels of risk, and therefore would not meet NASA's current health standards. The space agency commissioned a report ...
Intelligent warning systems may make 'dilemma zone' safer
2014-04-02
Most drivers have experienced a traffic signal that turns yellow just as they approach an intersection, which makes it difficult for them to decide whether to stop or proceed through it. The wrong choice in this critical situation, known as the "dilemma zone," may lead to crashes, especially at high-speed intersections. A new study published in Human Factors examines how intelligent warning systems help drivers negotiate the dilemma zone and encourage safer driving behavior.
"Intelligent systems could improve driver safety by potentially reducing crashes at signalized ...
Longer stay in hospital ICU has lasting impact on quality of life
2014-04-02
Patients have substantial physical impairments even two years after being discharged from the hospital after a stay in an intensive care unit (ICU), new Johns Hopkins research suggests.
The scientists found that for every day of bed rest in the ICU, muscle strength was between 3 and 11 percent lower over the following months and years.
"Even a single day of bed rest in the ICU has a lasting impact on weakness, which impacts patients' physical functioning and quality of life," says Dale M. Needham, M.D., Ph.D., an associate professor of medicine and of physical medicine ...
Drexel researchers open path to finding rare, polarized metals
2014-04-02
VIDEO:
Researchers in Drexel's College of Engineering have discovered a way to classify and predict the existence of a rare breed of electrically conductive polar metals.
Click here for more information.
PHILADELPHIA - Drexel University researchers are turning some of the basic tenets of chemistry and physics upside down to cut a trail toward the discovery of a new set of materials. They're called "polar metals" and, according to many of the scientific principles that govern the ...
A rainy day can ruin an online restaurant review
2014-04-02
After looking at 1.1 million online reviews for 840,000 restaurants in more than 32,000 cities across the country, Georgia Tech and Yahoo Labs researchers have found that the weather outside can be just as significant a factor for reviews as what happens inside a restaurant. Their study shows evaluations written on rainy or snowy days, or very cold or hot days, are more negative than those written on nice days.
"People love to describe themselves as foodies. But in the end, it looks like we're all weather people, whether we realize it or not," said Saeideh Bakhshi, a ...