Spiders are covered with fine hairs that can detect the faint movements of an enemy creeping closer, or a prey insect moving nearby. Scientists had long thought that these hairs functioned like the hairs humans have in our ears, which each tremble in response to a specific frequency and have to work together for us to hear sounds. But a new experiment suggests that each individual hair on a spider is capable of responding to a whole spectrum of sound, thus acting as an ear all on its own. As Dave Mosher writes at Wired:

The hairs responded best to sounds between about 40 Hz, a low rumble of bass, and 600 Hz, a car horn (humans ears can detect between 20 Hz and 20,000 Hz). That they picked up such a wide range of frequencies at all could overturn previous assumptions about how trichobothria [as the hairs are called] work.

“They operate like band-pass filters or microphones, not like the hairs in a human ear,” Bathellier said. In effect, each hair is its own ear that filters out background noise and zeroes in on biologically relevant information, such as an unwary cricket’s hopping or a spider’s sneaking.

How all these tiny “ears” work together, though, is still a mystery—further studies will have to investigate how the hairs’ vibrations affect spiders’ nervous systems.

Read more at Wired.

Image courtesy of timsnell / flickr

In the dreams of crime scene investigators, no doubt, they can feed a piece of hair into a machine and see a reconstruction of what the owner looks like. There’s a hint of that fantasy in the news that Dutch scientists have developed a test intended help police tell from a crime scene DNA sample the color of a suspect’s eyes. This information is gleaned from examining six single nucleotide polymorphisms, small genetic markers that are used in DNA fingerprinting, and could potentially help steer investigations when there are few other leads on a suspect and there is no match in police DNA databases. But the test, which can tell whether someone has blue, brown, or indeterminate (which encompasses green, hazel, grey, etc.) eyes with an average of 94% accuracy, doesn’t seem to have been tested outside of Europe, which raises questions about how well it would work in populations with greater diversity. It’s also a little hard to feature how you could bring this information to bear in a vacuum of other details—you’d want to avoid hauling someone in just because they looked suspicious and have the same eye color as the readout for the perp. At the moment, the test is not accurate enough to be introduced as evidence in court, which could be a bad thing or a good thing…depending on how many Philip K. Dick novels you’ve read.

Image courtesy of wetwebwork / flickr

Biologists have recently had cause to wonder whether the molecules they know and love are pulling some quantum trickery while they’re not looking: one of the large proteins that captures light in photosynthesis was observed in several studies apparently using coherence, one of the hallmarks of quantum mechanics, to determine the best possible route for shunting energy through its atoms. Now, further experiments that use lasers to tweak such proteins and observe their response have provided more evidence that this is happening—an exciting indication that the strange laws of quantum mechanics can affect the behaviors of large agglomerations of atoms.

Our own Sean Carroll of Cosmic Variance explained how coherence works when this phenomenon was observed in real plants at room temperature last year: (more…)

On November 28th Israel’s legislature unanimously passed a bill that outlaws the declawing of cats, except for certain medical reasons, making it a crime punishable by up to one year in prison and a fine of about $20,000 (or 75,000 shekels).

Declawing is a somewhat misleading term; in the procedure, called an onychectomy, the veterinarian typically removes all or most of the cat’s outer toe joint, bone and all. As declawing opponents have often pointed out, the human equivalent would be the amputation of your fingertips at or just above your third knuckle. Cats also use their toes/nails to walk upon; the Israel bill says the ban will help cats move around more normally, avoid certain medical complications, and defend themselves.

(more…)

What’s the News: We’ve long had signs that when it comes to inheritance, DNA isn’t the be-all, end-all. Trees that have the exact same genes but were raised in different greenhouses behave differently. Worms with genes that impart long life can pass on that longevity to their progeny—even if they don’t pass on the genes. Both of these phenomena, we’ve discovered, come from epigenetic changes in tags attached to DNA that control whether genes get expressed.

But every now and then we get a whiff of other possible routes for inheritance, even stranger than that. A new paper in Cell reports that worms whose grandparents had the ability to fight viruses using a fleet of tiny RNA molecules retain these molecules even when they don’t have the genes for them. They can pass these molecules down for more than a hundred generations.

(more…)

Before they can talk, babies use gestures to communicate: sentiments such as “take this away,” “look over there,” and “put me down” can be made abundantly clear without words. Chimps gesture to each other, as well, pointing out particular spots where they’d like to be scratched or groomed. These symbolic gestures are believed to be an important precursor to language. Now, researchers have observed ravens using gestures in the wild—the only non-primates seen doing so.

(more…)

Hardy Antarctic moss.

Ah, Antarctica. A vast expanse of ice, interrupted by mountains, ice… and more ice (with the occasional penguin). But in the East of the continent and on the Windmill Islands near Australia’s Casey research station, bare ground can actually be seen during summer months. Here Antarctica’s endemic plants dwell: lichens, terrestrial algae, and mosses. These smatterings of bryophytes are amongst the hardiest flora in the world, providing a home for a variety of minute life. They survive being covered in snow most of the year, only growing briefly during the summer months, watered by snowmelt. Except for in-person observations made over the last two decades, little definitive was known about these oases of diversity, like their age or how they might respond to changes in climate.

But now, some of the moss’s secrets are out. A recent study in the journal Global Change Biology found that some of these plants must be more than a century old, and a few may even be thousands of years old, said researcher  and study author Sharon Robinson via email. On average these mosses grow at the glacial speed of 1 millimeter per year—and some of the turfs are meters thick. That means many of these unassuming mossy carpets were there when humans first made it to the continent a century ago—and likely well before. “These mosses are effectively the old growth forests of Antarctica—in miniature,” Robinson said.

(more…)

Hookworms are longer-lived than viruses and bacteria;
they could have had a more significant effect on human evolution.

Humans live in all sorts of places—high deserts, tropical lowlands, frigid tundra. Over the millennia, you’d expect each population’s assortment of genes to evolve to reflect the demands and dangers of its home environment: those who live in the deserts would possess genes for extra skin pigments to help keep their tender integument from burning (like African peoples), and those who live in sub-zero climes much of the year would have genes that keep them well-insulated in fat (like the Inuit). But what if factors other than climate, like the food available nearby or the viruses, bacteria, and parasites native to the area, also had an effect on various human populations’ genetic toolkits?

It’s a fascinating question, but, given that we have to reconstruct all this supposed evolution from the current state of modern genomes, finding an answer isn’t easy. A recent paper takes an important first step by looking for correlations between 500,000 different genetic markers and certain environmental characteristics, like humidity, temperature, the local diet, and the prevalence of parasites and other pathogens.

(more…)

You can dream, but…lab-grown processed meats, let alone steak, are a very
long way off still.

Part of what stands between you and a lab-grown meat patty (a perennial source of fascination around here) is your gag reflex: the pale strips of cultured muscle cells that are currently the top contender for Petri-dish burgerdom look like scraps of mold, and they must be “exercised”—stretched between Velcro tabs—to strengthen and gain meat-ish texture. A patty made from them will be a hand-assembled stack of about 3,000 scraps, and in order to give the stuff color and iron, the lead scientist of the project opined to Reuters, they might need to soak it in lab-grown blood. Gah.

Still, factory farming ain’t pretty either, and the sheer amount of land and other resources we dedicate to meat production can be enough to make you gag as well.

(more…)

California birds are getting slightly bigger, according to a study published in Global Change Biology in which researchers measured and weighed 33,000 birds over the past 40 years. The increases were small, but significant: in the last 25 years robins have grown 0.2 ounces in mass and 1/8th of an inch in wing length, for example. But the finding runs counter to the only other long-term study measuring avian size in North America, which found that birds in Pennsylvania have shrunk slightly over recent decades. And it seems to disagree with other recent suggestions that animals may shrink in a warming world: Bergmann’s rule holds that animals generally get bigger as they get farther away from the equator, because larger animals are better able to retain heat.

(more…)

Above, the real deal; below, the clay models used to test predators’ reactions to local and foreign frog markings.

Sometimes, you have to make a thousand frogs from modelling clay to make your point.

A single species of poison dart frog sports ten completely different coloration patterns, depending on where they live. Are these color divisions being encouraged by the birds that prey on them?, wondered evolutionary biologist Mathieu Chouteau from the University of Montreal. To find out, he set out 1800 clay frogs, made by himself and his (saintly!) girlfriend, in the Peruvian forest.

(more…)

There’s a lot going on in Arctic permafrost as it melts and soil bacteria become more active. A new study explores how these bacteria may help or hinder our efforts to control the greenhouse gasses in the atmosphere.

What’s the News: Melting permafrost in a warming world could mean lots of greenhouses gasses, especially methane, released into the atmosphere. But it also means an unusual community of soil bacteria coming out of hibernation, so to speak. A new study looks at what those permafrost microbes do, exactly, as their environment warms up.

(more…)

The bacterium Micavibrio aeruginosavorus (yellow), leeching
on a Pseudomonas aeruginosa bacterium (purple).

What’s the news: If bacteria had blood, the predatory microbe Micavibrio aeruginosavorus would essentially be a vampire: it subsists by hunting down other bugs, attaching to them, and sucking their life out. For the first time, researchers have sequenced the genome of this strange microorganism, which was first identified decades ago in sewage water. The sequence will help better understand the unique bacterium, which has potential to be used as a “living antibiotic” due to its ability to attack drug-resistant biofilms and its apparent fondness for dining on pathogens.

(more…)

Because of two missing amino acids, this tomcod can swim through PCBs—and survive.

PCBs are nasty pollutants—they mess with hormones and have been linked to cancer—but until they were banned in 1977, dumping them in US rivers was a common practice for companies like GE. While plenty of wildlife suffered from ingesting PCBs, some fish in the Hudson and other be-sludged rivers evolved an immunity to the poisons, a intriguing example of quick adaptation that scientists have been watching with interest. A recent Economist article focusing on this research describes the fascinating genetic ju-jitsu that allows fish in the Hudson and in the harbor at New Bedford, MA, to keep themselves alive in PCB-contaminated waters. (more…)

In the Eastern Mediterranean, the pufferfish has arrived. And nobody’s too happy about it. The fish, also known as the silverstripe blaasop or Lagocephalus sceleratus, was first confirmed in Turkey in 2003 and has been spreading throughout the area. The problem with this unassuming fellow is that it contains tetrodotoxin, a neurotoxin that can be deadly to humans and for which there is no known antidote. Consumption of the fish has killed at least 7 people in Lebanon in the past few years, according to The Daily Star, and likely affected many more. A 2008 study found that 13 Israeli patients who ate the blaasop had to receive emergency medical attention at the hospital, where they didn’t recover for four days.

(more…)