Here’s a great idea for a super-power: what if by merely emitting a sound, you could detect nearby friends and enemies in the way the sound echoes? Echoes. Echoes.

For many species of bats and dolphins, echolocation isn’t a super-power but a necessity. It allows these animals to hear predators and prey without seeing them in the dark skies or cloudy oceans. This adaptation evolved separately in these mammals—a great example of convergent evolution.

Scientists at Queen Mary, University of London were curious how this type of convergent evolution looked at the genomic level. So they compared the complete genomes of 22 mammals, including new sequences of four bat species, to look at how echolocation is expressed in the genes.

To perform the analysis, the team had to sift through millions of “letters” of genetic code using a computer program developed to calculate the probability of convergent changes occurring by chance, so they could reliably identify “odd-man-out” genes.

Remarkably, they found genetic signatures consistent with convergence in nearly 200 different genomic regions! “We had expected to find identical changes in maybe a dozen or so genes but to see nearly 200 is incredible,” explains Queen Mary team member Joe Parker. “We know natural selection is a potent driver of gene sequence evolution, but identifying so many examples where it produces nearly identical results in the genetic sequences of totally unrelated animals is astonishing.”

Although many of the gene region similarities are in genes involved in hearing, which the team expected, others are all over the place, reports ScienceNOW:

…some genes with shared changes are important for vision, but most have functions that are unknown.

The team published their findings last week in Nature.

“These results could be the tip of the iceberg,” says group leader Stephen Rossiter. “As the genomes of more species are sequenced and studied, we may well see other striking cases of convergent adaptations being driven by identical genetic changes.”

So perhaps not a super-power, but a regular occurrence…

Image: Greg Hume

Not only are they the only mammals that can fly, but bats also show off with their immunity to viruses and other diseases. What gives?

Well, according to a recent study in Science, these two abilities—flight and immunity—might be related in the winged animals.

A group of international researchers sequenced the entire genomes of two species of bats—the fruit bat Pteropus alecto and the insectivore Myotis davidii. These two species are from the two distinct sub-orders of bats—P. alecto is a megabat and M. davidii, a microbat. By comparing and contrasting the two species’ genomes and those of other mammals (human, rhesus macaque, mouse, rat, dog, cat, cow, and horse), the scientists could refine bats’ place in the tree of life as well as determine the evolution of some of their bat-traits.

Study co-author Chris Cowled, of the Australian Animal Health Laboratory, describes how remarkable these traits are. “Bats are a natural reservoir for several lethal viruses, such as Ebola and SARS, but they often don’t succumb to disease from these viruses. They also live a long time compared to animals similar in size.”

It turns out the trick for this trait is flight. Flying is a very energy intensive activity that also produces toxic by-products, and bats have developed some novel genes to deal with the toxins. Some of these genes are implicated in the development of cancer or the detection and repair of damaged DNA.

“What we found intriguing was that some of these genes also have secondary roles in the immune system,” says Cowled. “We’re proposing that the evolution of flight led to a sort of spill over effect, influencing not only the immune system, but also things like aging and cancer.

“A deeper understanding of these evolutionary adaptations in bats may lead to better treatments for human diseases, and may eventually enable us to predict or perhaps even prevent outbreaks of emerging bat viruses,” says Cowled.

Sounds bat-tastic.

Image: James Niland/Wikipedia

By Zuberoa Marcos

White-nose syndrome has killed millions of North American bats. Now a team of U.S. scientists at The Nature Conservancy has built the first artificial cave in Tennessee to save them. The cave will open to the bats this fall.

About 5.7 million bats have already succumbed to white-nose disease in the US, according to the best estimates from state and federal wildlife officials. Originated by the aggressive Geomyces destructans fungus, it damages the bats’ wings and causes them to wake up when they should be hibernating. This burns their fat reserves too early, and the animals either starve to death or try to leave their caves in the dead of winter in search of food, often dying of exposure.

To date, there is no known treatment and the bats’ drastic decline has broad implications: the animals eat their weight in mosquitoes and other insects each day. By some estimates, they save American agriculture $3.7 billion annually.

The Nature Conservancy’s new hibernaculum hopes to protect bat populations. Made out of pre-cast concrete modules, it lies more than a meter below ground, stretches 24 meters in length, and could easily accommodate 200,000 bats.

To adapt to bats’ requirements, the cave was engineered to draw a continual supply of winter air from a concrete shaft to provide the chilly temperatures preferred by hibernating bats. The ceiling is scored with ridges and rough edges to give bat claws a tight grip. A rainwater pipe will bring in moisture to maintain the cave’s humidity levels and provide drinking water, and an air chimney will provide ventilation. Two 1.5-ton air conditioning units will run for the next few weeks to drop the cave’s temperature to the required range, between 41°F and 50°F.

The artificial cave won’t keep out the white nose fungus, but each autumn and spring, scientists plan to scrub it out with ammonia to keep it clean. Such a sanitizing procedure can’t be used in a natural cave environment because it would kill everything else and be detrimental to the ecosystem.

If the bat cave works, it will provide a new rescue plan for other endangered species. But there are no guarantees the bats will come in and use the artificial space. If they do, three surveillance cameras with infrared imaging will allow researchers to monitor bat movements without disturbing them. If they don’t, The Nature Conservancy’s experts can still use the cave as a field laboratory. They might bring some bats into the cave for testing new fungicides.

Zuberoa Marcos is a former biologist and current science writer based in Barcelona. She writes articles regularly for Science Today.

Un bunker para murciélagos

Por Zuberoa Marcos

El síndrome de la nariz blanca ha acabado con la vida de millones de murciélagos en Norteamérica. Un equipo de científicos estadounidenses de la organización The Nature Conservancy acaba de construir, en Tennessee, la primera cueva artificial para salvar a los que quedan. Empezará a funcionar este otoño.

Según estimaciones oficiales, alrededor de 5,7 millones de murciélagos en los EE.UU han sucumbido ya al síndrome de la nariz blanca. La enfermedad, originada por el hongo Geomyces destructans, daña las alas de los murciélagos y provoca que éstos se despierten cuando deberían estar hibernando. Esto hace que los animales quemen sus reservas de grasa demasiado pronto y, hambrientos, tengan que salir de la cueva, en pleno invierno, en busca de alimentos. Es una excursión mortal. Muchos de los murciélagos mueren por la exposición al frío.

Hasta la fecha, no existe un tratamiento para el síndrome de la nariz blanca a pesar de que esta drástica disminución del número de murciélagos tiene importantes consecuencias: los animales comen, cada día, su peso en mosquitos y otros insectos capaces de dañar los cultivos. Según algunas estimaciones, los murciélagos ahorran la agricultura americana 3.700 millones de dólares al año.

El nuevo hibernáculo protegerá a las poblaciones de murciélagos. Construido con módulos de hormigón prefabricados, está enterrado a un metro bajo tierra, tiene 24 metros de largo y podrá acomodar hasta a 200.000 murciélagos.

Para adaptarse a las necesidades de estos animales, la cueva ha sido diseñada para proporcionar un suministro constante de aire invernal y, con ello, las bajas temperaturas que les gustan a los murciélagos para hibernar. El techo consta de cantos y bordes ásperos para que los animales puedan agarrarse a ellos. Una tubería de agua de lluvia se encarga de mantener los niveles de humedad de la cueva y de proporcionar agua potable y una chimenea de aire de la ventilación. En las próximas semanas, dos equipos de aire acondicionado de 1.5 toneladas se encargarán de bajar la temperatura de la cueva hasta el rango necesario, entre 41 y 50 ° F.

La cueva artificial no impedirá que el hongo G. destructans entre en ella pero, cada primavera y cada otoño, los científicos la desinfectarán con amoniaco para mantenerla limpia. Este procedimiento de saneamiento no sería posible en una cueva natural, ya que sería perjudicial para el ecosistema y mataría al resto de habitantes de la misma.

Si la cueva artificial funciona, proporcionará una nueva estrategia para salvar a otras especies en peligro de extinción. Sin embargo, no hay garantías de que los murciélagos vayan a entrar y a utilizar el nuevo espacio artificial. Si lo hacen, tres cámaras de vigilancia infrarrojas permitirán a los investigadores vigilar los movimientos de los murciélagos sin molestarlos. Si ningún animal se instala en la cueva, los expertos de The Nature Conservancy podrán utilizarla como laboratorio, por ejemplo, introduciendo algunos murciélagos para probar nuevos fungicidas.

Zuberoa Marcos es bióloga molecular y actualmente trabaja como productora de TV y periodista científica. Escribe de forma regular para Science Today.

Reporting at the AAAS Meeting in Washington DC last week, the multi-disciplinary scientists discussed using radar to look at the aeroecology– the interactions of organisms in the lower atmosphere.

Using “doppler” weather satellites, a biologist like Winifred Frick of UC Santa Cruz is able to track the movement of Brazilian bats in Texas. These bats are important in the agriculture of the area– eating insects that would otherwise be crop pests. Frick stressed that these bats are observable in a cave, but not in-flight– they are too small for transmitters. But with the radar she was able to look at the broad scale migration and the phenological patterns across this particular population.

This information is essential to know as the climate changes because seasonal changes and conditions heavily influence the animals’ behavior. When bats emerge from their caves too early, they risk predation. When they emerge too late, they miss their dinner– the insects. With the radar data, Frick learned in dry conditions bats will emerge sooner, in wet, later.

The technology is incredible. Meteorologists can measure the amount of raindrops in a raincloud and now there’s an algorithm to figure out the amount of bats in a “bat cloud”. The radar can also distinguish between birds, bats and insects. Frick mentioned how she could watch the radar and see a cloud of pink insects fly over a bat cave and then follow a yellow cloud of bats emerge and overtake that pink cloud.

In addition, there is 20 years of data from these radars that the scientists can comb through to look for patterns in different areas for different species.

(Science in Action interviewed Dr. Frick on camera recently about the white nose fungus that is killing bats on the East Coast. Stay tuned for that story.)

Image: W. Frick/Central Coast Bat Research Group; (radar map, inset) SOAR

Earth

The Gulf oil spill—the number of gallons spilled and the controversy surrounding the damage seems to top many lists this year. Nature even named Jane Lubchenco, head of NOAA, its newsmaker of the year for how she handled the crisis.

Natural disasters often took the front page in 2010 with the Haitian earthquake and the eruption of Eyjafjallajökull topping many lists. The hard-to-pronounce Icelandic volcano also made many of the best science images of the year lists.

DiscoveryNews ends the year on a positive note with “How Humans Helped the Earth in 2010,” a slide show with text concerning recent strides in alternative energy, species and habitat conservation efforts and individual efforts to go green (electric cars, white roofs and saving energy).

For more environmental news of the year, New Scientist’s Short Sharp Science has a great review and the Nature Conservancy has a best/worst list on its site.

Life

Teeny, modified life stole the spotlight this year—the J. Craig Venter Institute’s so-called “synthetic cell” and GFAJ-1—the bacteria that incorporates arsenic into its DNA—or so NASA scientists claimed.  Science writer Carl Zimmer discredited the arsenic bacteria paper on Slate; NASA author Felisa Wolfe-Simon defended herself in Science. Fun stuff!

The spread of pesky bedbugs was number six in Discover’s “Top 100 Science Stories of 2010.”

Nature’s great article this past summer on eradicating mosquitoes was among its readers’ top choices of the year.

Looking for something a little bigger and less controversial? New Scientist has “The coolest animals of 2010,” which includes a scorpion-eating bat and a fly thought to be extinct for over 160 years!

NPR found it was a very good year for Neanderthals—their genome was sequenced, brain examined and diet expanded.

Remarkably, the Census of Marine Life tops the BP oil spill in the Deep Type Flow blog’s biggest marine science stories of the year for its sheer numbers:

…over 500 research expeditions covering every ocean, over 2,500 scientists and the discovery of over 6,000 species new to science and published in over 2600 peer-reviewed papers.

Space

ScienceNow’s most popular story of all time, not just 2010, was “Does Our Universe Live Inside a Wormhole?” A wonderful theory that we also covered last spring.

Exoplanets, in part thanks to the Kepler mission, were all over the news this year—whether it had to do with size, atmosphere or number within a star system. Discover’s interview with local exoplanet hunter (and California Academy of Sciences Fellow) Geoff Marcy made number 11(!) on their 100 top stories list.

A little closer to home, Jupiter’s missing stripe and Neptune’s tale of cannibalism are included in New Scientist’s most popular space stories of 2010.

Our Moon and Saturn’s moons made news throughout the year and the top lists on Universe Today and Wired this week.

Universe Today also included SDO’s new views of the sun in their top stories list. Stunning!

Hubble celebrated its 20^th year in space this year by taking even more beautiful images. Several are included in Bad Astronomy’s “Top 14 Astronomy Pictures of 2010.”

Technology

Electric cars and NASA’s new foray into commercial spacecraft are included in Scientific American’s top ten stories of the year.

The Large Hadron Collider was very busy this year, and topped many lists. Another machine at CERN made news (and also topped Nature’s readers’ choice list) when it was able to capture antimatter for a sixth of a second!

Graphene not only garnered a Nobel Prize this year, the material (and it’s potential) also made news and top science lists of the year.

DiscoveryNews put plastics on their 2010 list—whether its finding new ways of removing plastic from the oceans or engineering smarter plastics.

What was your favorite science story of the year? Share with us by adding it to the comment section below!

Image by Les Stone, International Bird Rescue Research Center/Wikipedia

Bats are not scary– in fact, what’s not to love about them? Echolocation, mosquito-eaters, they’re mammals and even kind of cute. (Well, maybe not this newly discovered tube-nosed fruit bat.)

But wait, there’s more. Recent research shows that their flight is much more complicated than that of birds and insects. Discover has a great online video demonstrating the process. And bats’ flight could inspire future aerospace technology design, according to the New York Times:

Further study of bat wings could help aerospace engineers develop tiny autonomous airplanes that are as flexible and acrobatic as bats… Today’s aircraft are large and have stiff wings, more similar to birds than to bats.

Other current research shows that bat echolocation goes beyond hunting—it’s also used to identify other bats.

More recent news about bats is sadly very scary. As cold winter weather begins to arrive, scientists are incredibly concerned about the further spread of White Nose Syndrome (WNS), caused by a fungus, that has killed over one million bats since 2006 in the eastern US. Current research suggests that the fungus disrupts the bats’ hibernation, causing them to awaken early, behave oddly, and lose critical fat reserves, resulting in death. One particular species, the little brown myotis, could quickly become extinct in some areas.

Eastern caves are being shut to stop the spread of the fungus. Though it travels from bat to bat, humans likely spread WNS, as well. It is possible that humans brought the syndrome to the US, since the fungus is found in European caves (European bats are not affected by WNS).

Because of the number of insects bats eat each day (more than half their weight), the effects of life without bats could be very dramatic, especially on agriculture. From a recent Popular Science article:

“Without bats, people are going to end up using more pesticides, there will be more water and soil contamination, more human contamination,” [Boston University researcher Tom] Kunz said.

You can help. Send a message to Interior Secretary Ken Salazar to get more funding for scientists studying and hoping to stop WNS. Build your own bat house to help protect your own bat-neighbors (with instructions from Bat Conservation International).

The world would be a very scary place without bats.

Scientists from Brown University and Japan report that echolocating bats traveling in large groups minimize sound wave interference by tweaking the frequencies of the sounds they emit — their broadcasts — to detect and maneuver around obstacles. The scientists also found that bats make mental templates of each broadcast and the echo it creates, to differentiate one broadcast/echo set from another. According to James Simmons of Brown, “They’ve evolved this, so they can fly in clutter. Otherwise, they’d bump into trees and branches.”

Meanwhile, in Germany, researchers from the Max Planck Institute for Ornithology found that the greater mouse-eared bat uses an internal compass and the Earth’s magnetic field to navigate in the dark. The fact that the greater mouse-eared bat does not use echolocation, even when hunting for food, makes this finding even more surprising.

The scientists don’t know how the bats detect the magnetic field, but according to New Scientist, “By exposing bats to a short pulse of skewed magnetic field during and after sunset,” they found that exposure “during sunset confused the bats, causing them to fly in the wrong direction, while experiencing it after the sun had set had no effect. This is strong evidence that the bats rely on the magnetic field while flying at night, after calibrating it by noting where the sun has set.”

So add radio broadcaster and astronomer to the list of bats’ amazing feats!

Creative Commons image by Vermin Inc