Cool Science

[libby]

The following is a book review from The Washington Post Science Scan on 4/12/16. It is absolutely fascinating.

Can squirrels count? That standard may not tell us much about animals' intelligence. -- by Frans de Waal

We love to compare the "intelligence" of various animals to that of humans, Frans de Waal notes: this chimp can count like a person, that parrot can talk like one.  But de Waal, a professor of primate behavior in the psychology  department at Emory University, thinks this anthropomorphic point of view is outdated, and he makes an entertaining, convincing case for each specie's intelligence on its own terms.

His new book puts it this way: It's unfair to ask whether a squirrel can count to 10 if squirrel life doesn't require counting.  It does, however, require remembering where hundreds of nuts were hidden, and the squirrel totally aces that -- while you probably forget where you parked your car.

De Wall, author of several books on primates and one of Time magazine's "100 Most Influential People" in 2007, is full of anecdotes about animal intelligence. Here's how killer whales hunt off the Antarctic Peninsula: A group of Orcas will spot a seal on a sizeable ice floe near land. Several of them work together -- and it's hard work, he notes -- to reposition the floe into open water. Then four or five line up side by side "and rapidly swim in perfect unison toward the floe, creating a huge wave that washes off the unlucky seal." Impressive. But the punch line's even better: A lot of the time the whales just release the seal -- and scientists have even seen them put one back on a different ice floe. Orca humor? Practical joke?

Lots of animals can recognize photographs of specific faces in their own species, de Waal reports, and crows can recognize -- and develop opinions about -- individual humans. One biologist in Seattle has captured so many crows for research that crows divebomb him when they see him outdoors. (He had his aides wear Halloween marks, but the crows learned to recognize those, too.)

And let's talk about dogs. de Waal knows some folks who own an Afghan hound and were enraged when the breed was ranked dead last in intelligence. "My insulted friends argued that the only reason Afghans were considered dimwitted is that they are independent minded, stubborn." The ranking wasn't about brains, the newspaper said, but obedience. Owners of border collies (No.1) may disagree.

The book is not only thought-provoking and full of information, it's also a lot of fun to read. It's title is Are We Smart Enough to Know How Smart Animals are?  -- and the author certainly is.

-- Nancy Szokan

[Anne]

That sounds like an interesting read. I will have to look for it next time I am at the library. Thanks, Libby.

[libby]

    Reading that review made me think of my son, who died several years ago. Before he became ill, he worked at Mt. Vernon, George Washington's home, which is nearby. His joy was working with the animals.

[libby]

 Reading the above book review also made me think of another book, Planet of the Apes, which inspired the movie by the same name. I read the book before I saw the movie, and it changed forever the way I think about animals. It was science fiction, written from the viewpoint of a human who was captured and treated like an animal, including being caged and watched and studied.

[libby]

"The Washington Post

Males may search for sex instead of food because their brains are programmed that way


By Elahe Izadi October 20, 2014

A petri dish containing C. elegans nemotodes (round worms) is prepared for examination by project scientists. 2003. Kennedy Space Center A petri fish containing C. elegans nemotodes (roundworms), from a 2003 experiment. These are the same kind of roundworms used in a recent study exploring sex-based differences in behavior (Kennedy Space Center)
There are some pretty basic building blocks to the survival of a species: that whole eating thing, and sex. Animals logically focus on both activities. But males prioritize the search for a mate over the hunt for grub, something that may be attributed to how their brains are programmed, according to new research published Thursday in the journal Current Biology.

For this study, researchers experimented on a microscopic roundworm (C. elegans) that has been used in labs for decades to understand the nervous system, with lessons applicable across the animal kingdom. They come in two genders: male and "females" (which are technically hermaphrodites since, in some cases, they can self-fertilize).

Scientists had previously discovered that the males and "females" end up making different decisions about feeding vs. finding a mate. The hermaphrodites prioritize finding food. But the males will "spontaneously leave a food source" to look for a mate in a lab setting, even "suicidally," ending up dead on a petri dish, said Douglas Portman, a University of Rochester associate professor and lead author of the new study.

Portman and others wanted to figure out just why the males did that. Could it be their genetic makeup, by virtue of being males, has programmed them to behave this way? Researchers zeroed in on the roundworm's sense of smell, and specifically, one particular gene that is related to receptors sensitive to the smell of food. The "females" produced more of these receptors, whereas the males just had less.

Researchers genetically modified a batch of males to produce more of the smelling-receptors, and compared them to normal males. "Females" were placed in the middle of a petri dish, and males were next to a food source on the edge of a petri dish, with another ring of food serving as a barrier between the two sexes. As expected, the normal males left their food source, went around the barrier and mated. But the genetically-modified males were much less successful at mating -- possibly because they were too busy eating.

Before you go thinking, "Ugh. Typical. Men," remember, it's not the male roundworms' fault! They aren't making a conscious decision to go mate instead of eat. "Part of the reason the males leave food to mate is that they don't smell it as well," Portman said.

Now what does this mean for other animals, including humans?  Well, people are way more complex creatures than roundworms. "Social and cultural factors clearly have a very strong -- and maybe even dominant -- contribution to sex differences in human behavior," Portman said.

But, we still don't know a lot about how the male vs. female human brain functions. Portman said there has long been "dogma" that behavioral differences has only to do with hormones, but "the brain also has access to that genetic information, of whether the brain is male or female," which may result in "subtle tweaks" that have big impacts on behavior.

"The extent to which there are innate sex differences in human behavior is still actively debated. And it really comes to the nature-versus-nurture question..," Portman said. "But there is a growing appreciation that there are biologically-based differences in the nervous systems themselves, and we understand very little where they come from."

The findings, which bolster the idea of "neural plasticity" rather than animals being hard-wired to do something that can't be altered, could have bigger implications when it comes to disease susceptibility for different sexes, Portman said.

"The bigger picture here is we're interested in the more general problem of how the brain works, how animals make decisions and how neural circuits are modulated to change the way animals make decisions," Portman said. "Surprisingly little is understood, really at the level of how the nervous system integrates all that dynamic information to allow it to make a decision."

[libby]

Why don't birds get lost? They may have mastered quantum mechanics.
  Huh? 

Sarah Kaplan
Friday, June 10, 2016
The Washington Post

Fascinating story.

"In the moment after their plane was hit, there was no time to think, let alone radio their position. The four Royal Air Force pilots ditched their broken bomber and dropped into the North Sea, near Britain. It was February 23, 1942 - and it should have been their last day on Earth.

Floundering in the frigid water, the pilots released their last hope: a tiny, bedraggled carrier pigeon named Winkie. She'd been inside a container the whole flight and was covered in oil from the crash. It wasn't clear that she would survive the 120-mile flight back home, or know how to get there.

But a few hours later, Winkie showed up at the home of her owner, who notified British authorities in time to launch a rescue mission. Without her, the four men might never have been found in the vast ocean.

So how did she do it?

"We think they are using quantum mechanics to navigate," said Daniel Kattnig, a researcher in the chemistry department at Oxford University. Kattnig works in a lab that studies radical pairs - a phenomenon in which atoms acquire extra electrons that are "entangled" with one another, each affecting the other's motion even though they're separated by space. It's a field of science that's difficult to understand under the best of circumstances; imagine trying to figure out it out with a bird brain.

But according to an increasingly popular theory, birds and other animals use a radical pair-based compass to "see" the Earth's magnetic field, allowing them to undertake great migrations and daring rescues without getting lost. It's still unproven, but Kattnig and his colleagues just verified a key component: In a study in the New Journal of Physics on Thursday, they report that the timing of these subatomic interactions makes them a good candidate to explain avian navigation.
"There are still many steps before we can say this for certain," Kattnig said. But this is one step along the way.

People have been trying to understand how animals know where they're going for more than 100 years. In a letter to Nature Magazine in 1873, Charles Darwin speculated that a sense of "dead reckoning" might allow everything from migratory birds to traveling tribes in Siberia to keep a course in rugged or unfamiliar terrain. Since then, scientists have proposed animal compasses based on sense of smell, memorized landmarks, the direction of the sun, polarization of light and even the positions of the stars. (It's been suggested that dung beetles plot a path back to their burrows by following the Milky Way.)

In the early 1960s, a German graduate student named Wolfgang Wiltschko set out to prove that birds navigated based on radio signals from the stars. During his experiments, he locked robins in a steel room with a Hemholtz coil - a device that produces a uniform magnetic field - and realized that the birds were reorienting themselves in response to it. He'd accidentally demonstrated that magnetism, not radio waves, was at the heart of animal navigation.

Those results sent scientists on a frenzied search for animals magneto-receptors. They discovered iron particles in the beaks of pigeons and hens, magnetite in the noses of trout, and other magnetic molecules in the ear hairs of birds.

Subsequent research found that some of those iron molecules were in immune cells rather than sensory ones, shaking up the migration-by-magnetic-molecules theory. But animal navigation scholars already had another possible mechanism: the radical pairs that Kattnig studies.

When the idea was first proposed by biophysicist Klaus Schulten, then of the Max Planck Institute, a reviewer at the journal Science wrote back to him, "A less bold scientist would have designed this piece of work for the wastepaper basket," he recalled in a history published by the University of Illinois.

"But there are lots of behavioral experiments that show this is actually a good fit," Kattnig said.

It's thought that light-sensitive proteins called cryptochromes - which have been found in the retinas of birds, butterflies, fruit flies, frogs and humans, among others - are at the center of the mystery. When light strikes the proteins, it creates radical pairs that begin to spin in synchrony; they're entangled.

The chemical reaction lasts only for a few microseconds, but Kattnig's research shows that it's long enough for the Earth's magnetic field to modulate the quality and direction of the electrons' spin. He also found that the radical pairs become more sensitive to the magnetic field as they "relax" - that is, as they transition back to equilibrium - if you take into account outside factors like ambient temperature.

This suggests to Kattnig and his colleagues that sensors in the bird's eyes survey the spin state of various radical pairs and then signal the results to the brain, allowing birds to more or less "see" the Earth's magnetic field as they fly through it.
There's still years of work to be done, Kattnig acknowledged. "We need to locate the spot where the cryptochromes are responsive to magnetism," he said. "And then we need to find the interaction partners - the cascade of signals which is then following up and giving rise to the visual impression."

"Lots of things are unknown," he concluded.

To scientists, maybe. The birds are finding their way just fine."

sarahkaplan@washpost.com

[libby]

I don't know if this belongs in this section or not. I find  it fascinating but also yuck, weird, gag....

Plastic bags???
The Washington Post

Speaking of Science

These pesky caterpillars seem to digest plastic bags
By Ben Guarino April 24

Holes in a plastic bag, the result of 10 worms chewing for 30 minutes. (CSIC Communications Department)

The shopping bag is an infamous source of plastic pollution. The 2010 documentary "Bag It" estimated that Americans use 102 billion plastic bags per year. Bags are persistent. Plastic at the waste dump can last for an estimated 1,000 years. And they are pernicious. A wild baby manatee named Emoji died in a Florida zoo in February after filling its guts with plastic bags and other litter. To curb our reliance on cheap plastic, Washington began levying 5-cent bag fees in 2009. Several other municipalities have followed suit.

Of course, plastic bags are useful, too. Federica Bertocchini, a biologist at Spain's Institute of Biomedicine and Biotechnology of Cantabria and a hobbyist beekeeper, used such a bag to collect pests called wax worms. The caterpillars, the larvae of the moth Galleria mellonella, had infested her hives, chowing down on honey and wax.

She plucked the wax worms from the beehives and dropped the caterpillars into a plastic bag — only to find "the worms all around and the plastic bag full of holes," as Bertocchini said in an email to The Washington Post. Bertocchini is an expert in embryonic development, not in caterpillars or things that chew through plastic. But the accidental discovery was too intriguing to pass up. The scientist contacted her colleagues at the University of Cambridge, Paolo Bombelli and Christopher Howe. "Once we saw the holes the reaction was immediate: that is it, we need to investigate this."

As the three scientists reported Monday in the journal Current Biology, the wax worms aren't simply chewing the plastic into tiny bits. Instead, it appears that the animals — or something inside them — can digest polyethylene, a common plastic, producing ethylene glycol.

"It was very exciting to find this, mainly because me and Paolo and Chris have been talking about this plastic biodegradation issue for a few years," Bertocchini said.

Their study was the most recent entry in a growing body of literature that suggests some organisms can process plastic. In 2015, scientists at Stanford University reported that mealworms, the beetle larvae used as fishing bait (and occasionally dusted with barbecue seasoning, as in eco-friendly snacks), can turn Styrofoam into carbon dioxide and droppings. In 2016, Japanese researchers discovered that microbes living close to a bottle-recycling plant could metabolize plastic.

Compared with the bacteria found near the recycling facility, "the wax worm is way faster, really faster," Bertocchini said. (When degrading plastic, though, speed is a relative term.) In the new study, it took 100 worms about 12 hours to eat their way through 92 milligrams of plastic, the mass of about three or four grains of rice.

To determine that the true source of wax worm power came from their guts, not their mandibles, Bertocchini and her colleagues reduced the caterpillars to a paste. They spread the stuff on a plastic sample. Over the span of 14 hours, the caterpillar schmear degraded 13 percent of the polyethylene mass.

Bertocchini speculated that the wax worms' predilection for honeycombs allowed the animals to process plastic. Wax itself is "a complex mixture of molecules," she said. Wax also contains a chemical bond found in polyethylene. "It may be that for this reason the worm evolved a molecular mechanism to break this bond."

The new report did not prove that the caterpillars were the responsible organisms. "At this point in time, we do not know if the caterpillars themselves are producing a digestive enzyme or might it be bacteria in their gut," Bombelli, a biochemist at Cambridge, wrote to The Post. "Or it might be a bit of both!"

(Nor did the study convince all biodegradation experts that animals can fully digest plastic. To the Atlantic, Michigan State Universitychemical engineer Ramani Narayan, who was not involved with this work, expressed concerns that wax worms could exacerbate problems by leaving tiny plastic crumbs in their wake. "Biodegradation isn't a magical solution to plastics waste management," Narayan said.)

But the authors of the new study do not envision dumping buckets of larvae over the world's landfills. Instead, they are attempting to home in on the wax worm digestive process. "If one molecule, one enzyme, is responsible for this reaction," Bombelli said, "we can aim at the isolation of the molecule."

That would be the first of several major hurdles the scientists would need to clear, to scale plastic biodegradation beyond a caterpillar curiosity. Once the researchers find the responsible enzymes and related genes, they would then need to "understand the optimal enzymatic condition," Bombelli said. Which is to say, what temperature and other conditions work best for worm-inspired digestion? What's more, an industrial scale requires a "cost-effective way of mass production." Perhaps, the biochemist said, engineered E. coli, common bacteria found in our own guts, could be coaxed into producing wax worm enzymes.

www.washingtonpost.com