0 comments on “Throat singing: a storm of sound on the steppes”

Throat singing: a storm of sound on the steppes

By Sam Jarman

The day dawns cold, clear, and still. A nomadic Mongolian herder knows that sound will carry well in these conditions, so he takes his chance. Climbing onto his horse, he rides into the wilderness, intent on finding a place where he can honour one of his people’s most sacred traditions. Using only his voice, he will imitate the song of birds, the hum of wind streaming over a rugged mountainside, and the hooves of wild galloping horses.

Finding the right spot is crucial. The herder needs to probe the nearby river valleys and mountaintops, to discover the place where his song will sound the most clearly.  If he chooses well, his voice could be heard for miles across the surrounding plains. He has learnt from his ancestors to use the Mongolian steppe as a sound studio; its open landscape providing the perfect acoustics to carry his voice. When he finds the right place, he begins his song.

His mesmerising chant often doesn’t sound like anything a human could create with their voice. The song could vary in pitch between being hauntingly deep, and as high as a flute. But astonishingly, he can sing both of these pitches, and many tones in between, at the same time.

For generations, people in Mongolia and surrounding areas in Siberia and northern China have learnt to use their voices to mimic the sounds of nature with a hypnotic accuracy. Even in the face of modernisation, the tradition remains as strong as ever today. It’s hardly surprising that the extraordinary talent of throat singing has become one of the most famous and iconic traditions in Mongolian culture.

Many Mongolians learn to throat sing from a very young age, but the techniques they use to produce such a bewildering array of sounds are anything but simple. To truly understand how they do it, we need to explore the anatomy of our own voices, and the physics of the acoustic waves we create with our vocal apparatus. Throat singers have learnt to intricately manipulate these acoustic waves to produce some astonishing sounds.

How it’s made: the human voice

Like any breath, or a normal speaking or singing voice, the song of a throat singer begins life as the lungs contract, forcing out a column of oxygenated air. The air travels upwards through the tube connecting our lungs to our throats, known as the trachea. But to distinguish the breath from a noiseless exhale, it first needs to pass through the larynx, sitting just above the trachea. The larynx contains a set of two vocal chords, which contract to a thin slit when we decide we have something to say, or rather sing.

Looking top-down: this little slit is responsible for every word you’ve ever said, even the embarrassing ones | Image: Henry Vandyke Carter

As air passes through the contracted vocal chords, they are forced to vibrate. These vibrations chop the air column up, forcing it to vibrate itself. At regular intervals, the air will be blocked entirely, and then be let through in a sudden rush. So, the air coming through the vocal chords vibrates in a pattern we are probably very familiar with: a sound wave.

The pitch, or frequency of these sound waves is ultimately decided by the size of our vocal chords. The tension in the chords, and the size of the gap between them, determine how much the sound waves they produce will vibrate over time. This gives them an important property, called the fundamental frequency ‚Äď a value which entirely defines the unique pitch of each of our voices.

The fundamental frequency is heavily dependent on gender. Women‚Äôs vocal chords are usually smaller, meaning the air column in the trachea vibrates more over time, giving the sound waves a higher frequency. For men, larger chords will cause the air column to vibrate at a lower frequency. But the fact that no two voices sound the same can’t be explained by variations in pitch alone.

A sound wave in it’s purest form – you can see how air is compressed and spaced out at regular intervals. This type of wave is easy to understand, but lacks emotional depth… | Image: Pluke

On top of a fundamental primary wave in our voices, there are many smaller, higher-frequency waves also created by the vocal chords. Called overtones, each of these waves has a distinctive frequency; the first will have twice the frequency of the fundamental wave, the second will have three times the frequency, and so on. When stacked on top of each other, all of these waves create one intricate and complicated sound wave. This is the sound of our voices, as unique to each of us as our fingerprints.

 

…The sound waves of our speech are much more complicated

Already, these sound waves can accurately express our emotions. When listening to other people, our minds can tell if their voice indicates happiness, sadness, anger, or surprise, simply by picking up subtle patterns in its loudness and variations in frequency. But to turn the sound waves into a coherent language, the air finally passes through our mouths. The continuous movements of our throats, tongues, and lips sculpt sound waves into the words we use to communicate with each other (here’s a pretty hilarious demonstration of how it works).

We use our vocal apparatus so often that we don’t need to consciously think about how we need to manipulate it to produce the particular sounds we want. But for Mongolian throat singers, the anatomy we normally use to talk and sing has untapped potential. The secret of their captivating sound lies in an important phenomenon in acoustic physics, known as resonance.

Resonance: a perfect storm of sound

Every object in nature has a natural frequency it vibrates at. Normally, any vibrations the object interacts with won’t have the same frequency as its natural frequency. But if the two frequencies match up (with a few physical constraints), the object’s vibrations can become much larger. One of the most famous examples of resonance is the bizarre collapse of the Tacoma Narrows bridge in 1940:

The reasons why the Tacoma Narrows bridge acted so strangely before collapsing have been strongly debated, and still aren’t fully understood. But the most agreed-upon theory is that patterns in the strong winds blowing across the bridge that day had just the right frequency to induce resonance in the bridge, causing a huge standing wave to form in the it’s road. Eventually, the bridge’s suspension cables gave out, but not before giving an outlandish display of the properties of physics.

In the case of our vocal apparatus, the natural frequency is determined by the sizes of the gaps which the sound waves of our voices need to pass through. If the wavelength of the sound is equal to the size of the gap, the gap itself will be forced to vibrate, creating its own waves with the same frequency as the original sound. All of the waves add together in a ‘perfect storm’ to amplify the sound, making it much louder than it was originally ‚Äď a resonant sound wave is formed.

Throat singers have learnt to manipulate parts of their vocal anatomy to produce resonant sound waves artificially. Different types of throat singing can cause resonance in different parts of the singer’s vocal apparatus. This creates a wide array of different types of throat singing, which each have their own name in the Mongolian language. The different styles are too numerous to cover in one article, but a smaller number of fundamental styles give rise to many of them.

Khoomei

In this style of throat singing, one or more of the smaller, higher-frequency overtone waves are caused to resonate as they pass through small, specifically-sized gaps in the singer’s throat and mouth. These waves are normally subtly engrained into our voices as individual overtones, but here, they can be heard as distinct, mesmerizingly clear sounds.

Astonishingly, the sound can be heard over the singer’s primary singing tone, meaning more than one note can be sung at a time by a single person. By the nature of our natural vocal sound waves, if we isolated all of the overtones which make up our voices, they would all be in harmony with one another. That means that the singer’s overtones create a one-person symphony without any further effort.

Typically in Khoomei, the singer will chant one continuous primary note, and then vary the overtones which are resonated. This creates a strong base sound, with a higher -pitched tune being sung above it. Mongolians believe the multiple tones of Khoomei give the impression of wind as it swirls around rocks and boulders, creating an enchanting natural chorus.

Sound: Alash Ensemble

Sygt

The highest of our natural overtones have far higher frequencies than anything a human could create with their natural voice. In this style, singers create a tiny gap between their tongues and teeth, to match the wavelengths of their highest-frequency overtones. The sound is shrill and piercing ‚Äď as close as the human voice can come to sounding like a flute.

Like Khoomei, this style involves a steady fundamental tone being sung, with the resonant overtone above it. Yet in Sygt, the high-pitched overtone dominates the song; the gap which sound waves need to pass through is so small that the primary wave is greatly diminished. To Mongolians, Sygt is intended to mimic the sound of birdsong, and the warm, gentle summer breezes over the steppes.

Sound: Alash Ensemble

Kargyraa

Situated right above the vocal chords are two folds of membrane which look similar to the vocal chords, but normally serve an entirely different purpose. The ventricular folds are there to prevent food and drink from entering our airways, but throat singers have learnt to manipulate them to produce one of their most iconic sounds of all.

By manually contracting their larynx to exactly the right shape, throat singers can bring their ventricular folds and their vocal chords together. So when air passes through the vocal chords, the ventricular folds will resonate themselves, producing their own sound. However, this resonance is unlike the effects seen in other types of throat singing; here, the ventricular folds vibrate at exactly half the fundamental frequency, creating an artificial undertone.

In musical terms, halving the frequency of a sound will bring it down an entire octave. This has astonishing implications for throat singers. Kargyraa singers can reach a wide range of notes far deeper than anything they could sing using their vocal chords alone. The effect is a haunting, low-pitched sound, reminiscent of rolling thunder, or the mournful cries of a camel after losing her calf.

Sound: Alash Ensemble

Kargyraa in particular can partly explain why throat singing still remains so popular in Mongolia today, and is even facing a resurgence. In the past, social taboos meant that women weren’t allowed to practice the tradition, but now, these barriers are breaking down. Female vocal chords may be smaller, but women can still contract their ventricular folds to create a fantastically deep sound:

Now that men and women have equal opportunities to practice the art, throat singing is being taught to boys and girls across Mongolia and the surrounding regions; all eager to pass on the traditions of their ancestors. The iconic sound has made its way into concert halls and recording studios, and in the West, throat singing has gone from a mysterious, alien practice, to one which is beginning to influence our own culture.

Anatomically, there is no special adaptation among the Mongolian people that enables them to throat sing better than anyone else. It’s no easy talent to learn, but we are all capable of recreating the effects of resonance on our voices, if we practice for long enough.

0 comments on “Lionfish wreak havoc on marine ecosystems”

Lionfish wreak havoc on marine ecosystems

By Roisin McDonough

Look at me. I’m the top predator now. | Image: Jens Petersen

The lionfish, beautiful in appearance and un-problematic in their native regions of the Indo-Pacific have wreaked havoc as an invasive species in the Atlantic; having become well established  in the Southeast coast of the US, the Gulf of Mexico and the Caribbean.

The Lionfish invasion was likely caused by humans releasing this popular ornamental fish from home aquariums when they were no longer wanted (over the course of 25 years). Their journey to the Atlantic was then possibly aided by the warm Gulf Stream  current which dispersed buoyant lionfish eggs and larvae further afield.

Warm currents like the Gulf Stream could be letting lionfish blag a cheeky ride to where they aren’t welcome | Image: Sommerstoffel

At first, their arrival into new areas was not considered to be much of a problem, as it was thought that that they would not survive very long. However, over the years, the lionfish have not just survived, they have thrived. Their success has led to the unfortunate and worrying decline of many native fish species and an alteration in the very delicate reef ecosystem.

Lionfish out-compete, out-live and out-breed native fish. But why?  For starters, they are highly tolerant to a range of temperatures, salinities and depths and biologically resistant to most diseases and parasites that affect native fish. Further, they have very few, if any, natural predators in the Atlantic. They become sexually mature at 1 year of age and can live in excess of 15, so have a long, rich reproductive life. In optimal conditions, females can release a staggering 2,000,000 eggs per year!

“Do you think that new guy looks dangerous?” “Who, the grumpy looking stripy one who’s at least 1000 times bigger than the rest of us?” “Yeah” “Nah, there’s something about his vast, leafy appendages I find sort of… comforting”¬†| Image: Alexander Vasenin

Lionfish are un-selective carnivores with voracious feeding habits, encompassing a huge range of small fish and crustaceans. Included in their diets are popular commercial fish like grouper and snapper and commercially important crustaceans such as lobster, crab and squid. In their non-native environments they have easy pickings when it comes to food, as generally, native species do not recognise the lion fish as a threat. In fact, some small fish will assemble around these invasive creatures in the hope that their fin rays/feathery pectoral fins will provide them with shelter and protection.

So far, lionfish hunting  seems to be the only feasible method of controlling their numbers. Certain areas which are regularly hunted see an increase in the number of native fish over time. However, the areas that can be reached by lionfish hunters is very small in relation to the vast marine environment lionfish now cover.

Invasive lionfish populations are an ever-growing problem – native marine life has suffered dramatic reductions as a result of their predation. Commercial fisheries, recreational activities and food security have also all been negatively affected as a consequence. We do not know the extent of the devastation to marine habitats in the near future, but it is likely to be bleak if their populations are not controlled.

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Touch nature

By Jonathan Farrow from the Thoughtful Pharaoh

I touched a rhinoceros yesterday; it was pretty awesome.

A real, live rhinoceros. His name is Shaka.

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Me and Shaka are basically best friends now. | Image: My own.

He was big, warm, rough, and surprisingly docile. He seemed gentle and easygoing, but I was also warned that it’s basically impossible to stop a rhino from doing what it wants to do.

I also met Shaka’s daughter Nomvula¬†and his baby mama Meru and now I’m in love with rhinoceroses.

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I love rhinos. Rhinos love hay. Does that mean I love hay now? | Image: My own

I had the privilege of getting up close and personal with a rhino yesterday because I have a friend who works at Knowsley Safari,¬†near Liverpool. My friend introduced me to the rhinos’ keeper, Jason, who spent half an hour with us, telling us all about rhino physiology, rhino breeding programs, rhino behaviour, and about the personalities of the Knowsley rhinos.

I learned that the name White Rhino is probably a mishearing of the dutch wijd, referring to their wide mouths (although some parts of the internet disagree). I learned that the horns were probably once used to dig up tubers and aren’t usually used in fights. I learned that it takes five years before a rhino trusts you enough to tolerate you.

It was all supremely interesting, but the thing that stuck with me most and the thing I want to write about is the feeling of touching a wild animal.

Connecting with nature

Actually meeting a rhino connected me to them in a new way.¬†I had read about poaching issues, about the price of rhino horn, about conservation programs. But it all seemed so remote. I cared, but I didn’t really care.

This sense of connection after exposure has been shown with nature more generally: the more time you spend in natural environments, the more likely you are to care about nature and the more likely you are to do things that help it.

Most people tend to appreciate nature already, but there are plenty of selfish reasons to take yourself outside more often. Connection with nature is associated with decreased rates of depression, increased intelligence and faster recovery rates in hospital. People who live close to green space are healthier Рphysically and mentally.

Because of this, some researchers argue that encouraging people to protect the environment would be a solid public health policy.

Social Psychology

So, now knowing all these facts about the benefit of nature, why did it take actually touching a rhino for me to feel connected with nature? There are probably lots of reasons, but I think there are two interesting answers from social psychology: the mere exposure effect and lessons from prejudice research.

The mere exposure¬†effect is a well-studied phenomenon in psychology. People tend to like what they spend time around.¬†It’s why Justin Bieber gets better the more you listen to him. We like familiarity. In a famous 1968 paper¬†that established the effect, Robert Zajonc presented the results of several experiments. This included one where¬†people preferred nonsense words that they repeat more than ones they only say once.

The intuitive truth of this effect is borne out in the advertising industry. While there are other bits of psychology at play in any given ad, ultimately the more you see a brand, the more you will like it. In the same way, I think the more people are exposed to nature, the more they appreciate it.

But this doesn’t explain why just one amazing encounter with a rhino could have such a deep impact on me, for that we need to take a look at research into inter-group relations.

When two groups hate each other, the way to overcome prejudice is to make meaningful contact between the two groups. This is well-established, but a recent meta-analysis of over 500 papers on the topic looked at why contact reduces tension. The three theories were because it brought increased knowledge of the other group, because it reduced anxiety about the other group, and because it allowed people to have empathy with the other group.

While all three were shown to be valid¬†reasons why contact combats¬†prejudice, the second two had the strongest effects. This makes sense in the rhino context. I could learn all the facts about rhinos, but until I got close to one, I wasn’t sure if they would hurt me and I couldn’t empathize with them. I didn’t¬†care about them.

It’s hard to hurt something¬†you care about.

So get outside and hug a tree more often. If you touch nature, you’ll be healthier, happier, and more likely to do it again. Virtuous circles¬†for the win.

0 comments on “Design, Naturally: Lateral lines provide a sixth sense for underwater robots”

Design, Naturally: Lateral lines provide a sixth sense for underwater robots

By Anwen Bowers

More little fish swimming in a school.
“We turning left now?” “Yeah, you do know we have a sophisticated biological mechanism for finding that out, right?” “I was just asking for a friend” | Image: Tom Thai

Have you ever seen two fish bump into each other?

The underwater world is an assault of sensory signals. Sound, for example from crashing waves, travels over twice as fast in water than it does in air. Smells, ranging from mating hormones to decaying organisms, clash against each other like instruments in an orchestra and would be overwhelming to us if we had noses sensitive enough to detect them. Light is changing constantly, with the different wavelengths becoming increasingly filtered out with depth until animals are left navigating waters so dark that they would be impossible to penetrate with human eyes.

But despite the chaos, fish are able to identify predators, prey and potential mates with lightning reflexes and take the appropriate action within milliseconds.  This is thanks to a super-human sensing mechanism called the lateral line, which gives the fish a sixth sense with which to navigate in their watery habitat.

lateralline
A subtle stripe of hair can tell fish everything they need to know about their environment | Image: Pogrebnoj Alexandroff

Sometimes visible as a dark strip running along the fish from fin to tail, the lateral line consists of minuscule bundles of hair that can be either attached to the surface of the scales or slightly submerged in channels below the skin. These hairs work similarly to whiskers on a cat, bending in response to any change in the flow of water around the fish. Cells at the base of the hairs then send messages to the brain, containing information on the scale, speed, and direction of the disturbance. This can then be interpreted to give information about the size and shape, and therefore species and likely friendliness, of anything moving in the local area. The ability to identify friend from foe by the flick of its tail is an invaluable tool of survival.

Seas and oceans are one of the least understood habitats on earth, with vast areas being simply too inaccessible to explore. As space on land is becoming rapidly exhausted, we are extending further and deeper into the oceans to source food, generate energy and hunt for new minerals and medicines. Faced with challenges such as the extreme pressure and low temperatures, increasingly we are depending on the work of underwater robots to bring us information on the chemistry, physics, and biology of the deep sea.  Engineers looking to improve the performance and capabilities of these underwater robots have found inspiration in the lateral line to improve the performance of these robots.

robofish
Bass-ta la vista, Ray-by: artificial lateral lines have inspired highly sensitive robotic fish | Image: Titus 140

Researchers in Germany and the US have independently come up with two different systems that recreate the processes that take place in the lateral line hairs. Integrated into underwater robotic technology, these systems could create a robot with much greater perceptions of their surroundings. Traditionally, operators would rely on images from video and sonar to navigate and direct the actions of the robot underwater. Both of these technologies are limited, as they can only provide information on the small area that they are pointing at Imagine only being able to view the world through a toilet roll tube ‚Äď it‚Äôs a bit like that.

Lateral lines could provide a much more detailed 3D picture of the surrounding environment, allowing more informed decisions about how the robot should proceed. The more information available about the surrounding area, including any obstacles, the greater the chance of the robot completing its mission as efficiently and safely as possible. For example, if the battery is running low, the lateral line would be able to identify nearby areas of low water movement where the robot can go to rest and conserve energy out of the current. Taking inspiration from nature, and building robots that can sense like fish, scientists can expect to soon be announcing plenty more exciting discoveries from the mysterious deep ocean.

0 comments on “Natural Cycles: Part 1 – The circle of life and waste”

Natural Cycles: Part 1 – The circle of life and waste

By Anwen Bowers

north-pacific-gyre
Circulation patterns in the North Pacific have created a vast plastic continent | Image: Steven Guerrisi

The Great Pacific Garbage Patch is a vast area in the Pacific Ocean where huge amounts of plastic and other slow-to-degrade waste has accumulated over the past half century. Rubbish from all the rivers in North America and Asia gathers here and then becomes trapped by the swirling waters of the North Pacific Subtropical Gyre.

The plastic has nowhere else to go, and so it circles around the oceans, breaking down into smaller and
smaller pieces; small enough to be consumed by the plankton, fish, birds and mammals of the Pacific Ocean. This poses a huge environmental threat, and it is a result of the linear processing of waste that is a uniquely human phenomenon.

In nature, everything is processed in cycles *cue famous Disney soundtrack*. As animals feed, the basic building blocks of life are passed up the food chain, and when the top predators die or defecate, the cycle starts again. Every single atom in our bodies has already passed through a number of incarnations, already been part of an ant or a daisy or a rock, and has the potential to become so again.

vultures
They may look sinister, but vultures are nature’s recyclers; they are vital in many ecosystems | Image: Hugh Lunnon

Many organisms have carved out an ecological niche for themselves facilitating this cycle. Animals like vultures and dung beetles may not have the most glamorous rep, feeding as they do on dung and rotting corpses. But in so doing they remove a source of harmful bacteria and disease, turning it instead into bioavailable nutrients, promoting growth, habitat, and life. Unglamorous it may be, but an invaluable service nonetheless.

Where nature operates on complex, closed systems that generate zero waste, humanity tends to operate on a linear system. In this system, materials are processed into products that are useful for a time, but once they reach the end of their life span the waste is packed into crevices in the earth’s crust, or swept into oceans, never to be useful again.

This is unsustainable not only because these endpoints will eventually become saturated, but also because by taking the materials out of circulation, we are effectively putting an end to their reincarnation cycle. The more stuff that is floating in the Great Pacific Garbage Patch, the less stuff we have to use, and logic follows that we will eventually run out.

caviar
Turning empty cardboard boxes into gourmet dishes: restaurants could have a lot to gain from the circle of life | Image: Lebensmittelfotos

Luckily, more and more business models are starting to see that that by following nature’s example they can simultaneously increase productivity, whilst decreasing harmful output. Cardboard to Caviar is an initiative set up by the Green Business Network (GBN) in West Yorkshire. Inspired initially by the problem of waste cardboard packaging from the restaurant industry, GBN’s solution was to collect the cardboard, shred it and sell it as bedding for horses.

A good solution, but what about the waste that then came from the stables? GBN started to collect that too, feeding it into giant composters, where the cardboard and manure were broken down by worms. The worms, in turn, are fed into GBN’s fish farm, where they are eaten by sturgeon, which produce caviar that is sold…to the restaurant industry!  

The number of businesses that process waste into something useful appears to have increased exponentially over the last few years. They’re turning chopsticks into furniture and plastic bags into bricks.

However, a word of caution: Whilst these examples should be credited for their innovation in extending the life of waste materials, they are still, in essence, linear. The risk is that whilst storing plastic in bricks is better than storing it in the ocean, we could ultimately also be storing up the problem for future generations. Plastic, in particular, can only be recycled into a useful product once; any further processing deteriorates the quality too much.

To effectively transition into a low waste society, there also needs to be a parallel shift towards sustainable, natural materials that can either be cycled in themselves or converted into new materials, continuing the circle of waste.

0 comments on “Design, Naturally: Wasps take the sting out of brain surgery”

Design, Naturally: Wasps take the sting out of brain surgery

By Anwen Bowers

‚ÄúI cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonid√¶ with the express intention of their feeding within the living bodies of caterpillars ‚Ķ‚ÄĚ

This statement from Darwin is often quoted in discussions about his changing relationship with religion as he developed his theory of evolution. 150 years later, the ichneumonidae in question are taking a step towards shedding their demonic reputation by inspiring a new approach to neurosurgery.

| Image: Sean McCann
Pretty deadly. We could look at ichneumonidae ALL DAY.| Image: Sean McCann

The ichneumonidae are a subfamily in possibly the largest group of animals in the world ‚Äď the parasitoid wasps. Estimates of the total number of ichneumonidae species alone reach up to 100,000 ‚Äď more than all the vertebrate species in the world. The wasps gain their name because they¬†brutally kill their host species, as opposed to parasites which drain the resources of an organism without causing significant harm.¬†Indeed, life histories of the parasitoid wasps are close to the stuff of nightmares.

The extremely high diversity of ichneumonidae has arisen because each species of wasp has evolved to target just a single type of prey, and to do it as efficiently as possible. Each species is distinguished by its specialised weaponry or tactics that allow them to tackle their prey in their niche habitat or lifestyle. For example, Lasiochalcidia igiliensis’ chosen host is the antlion larva, a ferocious predator in its own right with vicious jaws that it uses against a range of arthropod prey, even spiders.

antlionlarva
A badass Antlion larva clearly has only one thing to fear. Fear of L. igiliensis itself. | Image: Larah McElroy

The seemingly fearless L. igiliensis has been observed to bait the antlion larva, encouraging it to attack the wasps itself. At the point of attack, the wasp will use its powerful legs to prise the jaws of the antlion open, whilst simultaneously depositing an egg into the antlion larvae’s throat. There the egg will incubate, feeding on the antlion from the inside, until the time for metamorphosis comes. At this point the wasp will burst out from the antlion, not unlike the infamous scene from Alien.

Strategies in other species include a fibrous mesh that traps air allowing the wasps to dive down and reach caddis fly in their underwater habitat, and a hormone invisibility cloak that allows the wasps to live within an ants nest, even up to adulthood, without detection. These guys are the Q Branch of the insect world.

M. macrurus prepares to drill. | Image: Evan Kean
M. macrurus prepares to drill. Just look at that ovipositor. Stunning, and inspiring… | Image: Evan Kean

Here at Rising Ape we can vouch from experience that great ideas happen when you put a bunch of scientists from different backgrounds in a room, and maybe give them a bottle of wine. This seems to be what happened in the case of Dr Ferdinando Rodriguez y Baena, a medical engineer who found himself inspired by a serendipitous dinner party conversation with zoologist and biomimetics expert Julian Vincent.

Vincent described how the parasitoid wasp species Megarhyssa macrurus, is able to use her egg laying tube to drill down into tree bark, where she deposits her eggs onto the larvae of the pidgeon tremaz horntail (how did this come up as a topic?! Over dessert?). This is possible thanks to a complex structure of three tubes that can bend and flex as the wasp drills, allowing her to position her eggs with pinpoint precision.

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The three parts of this needle echo the ovipositor of the drilling wasp and give it unparalleled flexibility. | Image: UCL

This elegantly specialised structure gave Baena the idea for a new style of needle that mimics the ovipositor. The design allows surgeons to control and manoeuvre the needle inside the patient, navigating around sensitive and fragile parts of the brain. This minimally invasive surgical procedure could even allow surgeons to deliver drugs to very specific areas in the brain, potentially treating diseases such as brain tumours and Parkinson’s. By saving lives for a change, the ingenious ichneumonidae wasps could be about to improve their reputation.  Who knows, even Darwin may have approved.

0 comments on “Design, Naturally: Sharkskin V Superbugs”

Design, Naturally: Sharkskin V Superbugs

By Anwen Bowers

Antimicrobial resistance is one of the biggest challenges faced by the healthcare industry. The evolution of superbugs such as MRSA is evidence that the arms race between antibiotics and bacteria is not a sustainable strategy for preventing infection and keeping patients healthy. Bacteria are able to make infinite changes to their DNA, but¬†there isn’t an infinite supply¬†of new drugs available to target them. Scientists looking for alternative methods to tackle the spread of disease causing bacteria have turned to the natural world for inspiration.

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Opens doors, spreads diseases, can be opened by velociraptors. | Image: Public domain

Bacteria in hospitals spread through contact. If a person touches a surface that hosts bacteria, they can pass it along next time they touch a piece of equipment, or a patient. So could making surfaces inherently resistant to bacteria be an effective way of stopping the transfer and spreading of disease?

Traditional approaches to keeping surfaces sterile involve using some sort chemical agent, for example treating socks with silver to keep smelly feet at bay (equally effective against vampires). The disadvantage of chemical treatment is that protection is short lived, and needs constant renewal. Research suggests that silver nanoparticles in socks last not much longer than a few washes, as the silver is rinsed out into the environment where it becomes a poisonous threat to wildlife.

In a paradigm shift in strategy, scientists have proposed a new mechanical approach to keeping surfaces clean. Taking inspiration from the sea, they want to develop a texture that prevents bacteria from spreading by discouraging microbes from settling in the first place.

dirty boat hull
Hull is filthy. The boat’s hull that is. | Image: Glenn Batuyong

Place almost anything underwater and it won’t be long before a thin film of green slimy phytoplankton will start to settle. This plankton is the trigger for a chain reaction of settlement, as larvae of adhesive animals such as anemones and barnacles will soon follow. This has long been a problem for the shipping industry as fouling like this on ship’s hulls creates a huge amount of drag, slowing down the vessel and adding fuel costs. Even whales, despite their constant movement, will succumb to the nuisance of barnacles and parasites.

But scientists observed that sharks remain clean and crust free, even into old age. For a long time it was thought that sharks move too quickly through the water to give anything any time to settle. Closer inspection of the surface of their skin provided an alternative answer. Sharks are covered in specialised scales called dermal dentacles.

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Sharks: Creating the worst place for bacteria to hang out for 100 million years | Image: Pascal Deynat/Odontobase

Dentacle means ‚Äúsmall tooth‚ÄĚ, a name derived the¬†dentine tissue from which they’re made¬†and the same found in your teeth. Dermal dentacles are highly textured, and when meshed together they form an extremely complex surface, full of micro mountains and canyons. This surface appears to be too unstable for any bacteria to settle and establish a community effectively.

Without the base layer of microscopic organisms, the bigger problem of larger, fouler organisms cannot develop, and the¬†shark remains clean and smooth. This evolutionary advantage then¬†helps the seas’ top predators¬†move¬†swiftly through the water in pursuit of their prey.

640px-Prionace_glauca_by_mark_conlin.JPG
‘Phelps who? Bet I’m cleaner and¬†faster.’ | Image: Mark Conlin

Shark skin is already well studied, and has inspired a range of products, famously the Olympic grade swimwear that can reduce drag and shave milliseconds of a swimmer’s time. To use it as a surface for hospitals was the idea of Anthony Brennan, founder of the company Sharklettm , who have trademarked a textured pattern based on the structure of sharkskin. The company claims that Sharklettm surfaces harbour 94% less bacteria than standard worktops and equipment.

Installed in places such as drawer handles and even surgical equipment, Sharklettm could be a cost effective way of reducing the spread of bacteria, as well as use of antiseptic and not to mention the time staff spend cleaning surfaces. What has evolved over millions of years could be a solution to a very pressing 21st century issue.

0 comments on “W is for Wasps”

W is for Wasps

It’s summer time. ¬†And you know what that means? Sure, summer means picnics, barbecues, and sun.

But it also means the coming of the most dreaded outdoor villains: wasps.

Some people freeze up when they see the stripey serial stingers, others try to wave them away. ¬†I prefer the stoic strategy of a short, sharp yelp followed by a crazed hand-waving motion. ¬†It’s not a conscious decision, nor one that I am proud of, but the wasps seem to get the idea that I don’t want them around.

What is a wasp?

Wasp_morphology.svg
Image by Stannered

In taxonomic terms, a “wasp” is any member of the suborder¬†Apocrita¬†that isn’t a bee or an ant. ¬†While that may help useful for biologists, it doesn’t really tell us anything about the creatures.

Wasps are a varied group of hairless, six-legged flying insects that measure anywhere from to 1mm (Fairy Wasp) to 4.5cm (Japanese Hornet).  There are thousands of species of wasp, many of which are specially adapted to feed on and parasitize insects we would regard as pests.

Parasitism

And the way they parasitize those pests can be cruel indeed.  Some parasitoid wasps lay their eggs inside their prey, only to have the eggs hatch a few weeks later, letting their young eat their way out of the unsuspecting caterpillar that has been feeling a strange itch recently.

Other wasps lay their eggs inside plants, genetically modifying a plant’s¬†seeds to suit the wasp’s¬†needs.

Still other inventive wasps have figured out that they can lay their eggs in the nests of other wasps and trick another queen into raising their young.

It seems there is nothing a wasp won’t lay its eggs in.

Fighting Wasps

Not all wasps are content merely laying eggs in unusual places.  Some have acquired a taste for honey.

Meet the Japanese Giant Hornet.

While European honeybees haven’t developed defenses, asian honeybees have discovered a way to fry invaders.

So while you may just think of them as a nuisance when you’re trying to enjoy your picnic, remember that with wasps, there is more than meets the eye.

0 comments on “T is for Tardigrade”

T is for Tardigrade

By Jonathan Farrow from the Thoughtful Pharaoh 

Boil ’em, mash ’em, stick ’em in a stew.¬† They’re versatile!

No, I’m not talking about taters. ¬†I’m talking about tardigrades: quite possibly the most durable¬†creatures on Earth.

They might also be the strangest combination of cute and terrifying anybody has ever seen looking through a microscope.

Cute and terrifying.  Image by Abribus
Meet the water bear.  Strange combination of cute and terrifying. Image by Abribus

Tardigrades, also known as water bears, evolved 500 million years ago. ¬†They have survived on a diet of moss and lichen since around the time¬†the first fish evolved and shortly after animals evolved at all. ¬†While their basic body plan hasn’t changed much, they haven’t been evolutionarily idle. ¬†They’ve developed some pretty neat¬†adaptations (some of which will be discussed below) and diversified into over 1000 unique species. One thing all¬†of these species¬†has in common is size: all species of tardigrade¬†measure¬†between 0.1-1 millimetre (comparable to the size of a single salt crystal).

The amazing thing about these itty-bitty balls of chitinous cuticle is that they can withstand pretty much every type of extreme we can cook up. ¬†They’ve been boiled to over 150 degrees celsius without breaking a sweat. ¬†They’ve been frozen to -250C and didn’t need tiny parkas. ¬†They’ve been dipped in acid, shot into space, dried out, and zapped with thousands of times the lethal radiation dose for a human and they just kept chugging.

Why won't you die!? Image by Frank Fox
Why won’t you die!? Image by Frank Fox

Why are we being so cruel to these tiny creatures?  Because they keep surviving.  Things that terrify us and would kill almost any lifeform barely even faze them.  Tardigrades have expanded the notion of habitable environments and understanding their indestructibility has profound implications for both earthbound medicine and for life on other worlds.

I think tardigrades are pretty darn cool.  This is likely due in no small part to the fact that the lab where I did my thesis in undergrad was home to a healthy colony of moss-eating tardigrades.  Up on the third floor of the Life Science Building at McMaster University, my former supervisor, Dr. Stone (or Doc Roc as he likes to be called) has been testing tardigrade tolerances with Taru, his PhD student.

“Ewww, you can see all of its insidey bits” – Me, the first time I looked at a tardigrade through a microscope. Image by Daniel Adrian Ciobanu, Krzysztof Zawierucha, Ioan Moglan, and ŇĀukasz Kaczmarek.

I got in touch with Doc Roc this week to ask him a few questions about tardigrades. ¬†To give you an idea of the kind of (awesome) professor he is, one of his research goals was to publish a one-sentence paper. ¬†He accomplished that goal with the help of quite a number of semi-colons. ¬†As you’ll see below, I think he likes that useful but oft-forgotten punctuation mark.

Thoughtful Pharaoh (TP): Where do you find tardigrades?

Doc Roc (DR): Tardigrades are found the world over, literally on all continents and in all bodies of water; they inhabit all systems, marine, freshwater, terrestrial; they occur terrestrially on moss.

[They’re everywhere!]

TP: What have you done to test the limits of tardigrades?

DR:  We have tested their tolerance to temperature (cold), radiation, desiccation, pH, g-forces (simulated), and red food dye (I think that you know the tale); we have witnessed complete revival from -80 degrees Celsius for up to 6 months (but they can tolerate -250 K); 4000 Gy radiation (6 Gy kills humans); completely drying out inside an evaporating water droplet (tales in the literature purport over 100 years in a desiccated state); over 16000 g (Earth atmosphere being 1 g Рmeteoritic impact being an order-of-magnitude greater, however); and sensitivity to red food dye.

[The tale of the red food dye: In one of many discussions of tardigrades in that lab, I was asking if these incredible creatures had any weaknesses.  Doc Roc told me about a curious incident that happened when he tried to stain tardigrades to see them better.  He tried putting some red food colouring onto the plate and they changed colour and were easy to spot, but they also all died. Green and blue food colouring did nothing, but red colouring stressed the tardigrades to death.  Strange that such an indestructible creature could be undone by food colouring.]

TP: What is the most interesting thing about tardigrades, in your opinion?

DR: I think that understanding how their tolerance and reproductive modes (e.g., parthenogenesis) evolved are the most interesting topics for tardigrade research.

[Tardigrades don’t need males to reproduce. ¬†Females can lay unfertilized eggs which will hatch as clones, genetically identical to the mother. ¬†The advantage of this is that they don’t need to waste time looking for mates. The disadvantage is low genetic diversity.]

TP: What do you want to do next?

DR: We plan to investigate how they tolerate the high radiation doses (e.g., their DNA repair mechanisms).

[McMaster has a small nuclear reactor on campus, which has been used in recent years to expose tardigrades to high levels of radiation.  After thousands of times a lethal radiation dose for humans, the tardigrades were fine and in some cases the irradiated ones did better than their lab-housed control counterparts.  How they can survive and continue to reproduce remains a mystery but it almost certainly involves some incredible DNA repair.]

TP: Do you ever name the tardigrades?

DR: The student who studies them is named Taru, which seems an appropriate name for one; given that we work with a parthenogenetic species, I would name them Tarugrade 1, Tarugrade 2, …

[Seems reasonable to me.]

TP: If they’re so invincible, why haven’t tardigrades taken over the world?

DR: Organisms are limited in their resources, so populations can grow unchecked only to the extent that living materials are available (populations crash thereafter); predators additionally can reduce population sizes.

[In other words, tardigrades can still starve and get eaten.  Just like every other creature.]

TP: What can studying tardigrades tell us about life on other planets?

DR: Studying tardigrades can inform us about the limits to which organisms can survive, helping researchers to identify which extreme environments are viable and whether organisms could be transported between planets.

[The theory that life arrived here from another planet (called panspermia) is not as crazy as it sounds.  I wrote a bit about it a while ago.]

Thanks Doc Roc!

If you have any other tardigrade questions, feel free to comment below and be sure to share this with your friends. Spread the water bear word and let us not be frightened of our tardigrade overlords!

Tardigrade 1
This guy looks like he’s ready to partygrade. Image by the Goldstein lab.

If you want to learn more:

  • The BBC recently published a pretty comprehensive article about these resilient little critters here
  • TARDIS was a European mission in 2007 to see how well they survived in space
  • A (bearded!?) Hank Green produced a video about them for SciShow in 2012.
0 comments on “S is for Simple Rules”

S is for Simple Rules

By Jonathan Farrow from the Thoughtful Pharaoh

Consider the following: schooling fish, roundabouts, segregation, and human consciousness are all examples of the same fundamental property of the world.  It may seem crazy to suggest that roundabouts may be interesting in some sense, but bear with me.

The property in question, and this week’s topic, is emergence. ¬†In each case individual entities, by following simple rules, can create complex patterns of behaviour. ¬†What makes these patterns special is that they can’t be predicted based on the simple rules alone.

Swarms

If you’ve ever seen a murmuration of starlings, you have probably found yourself wondering how that many birds (upwards of 100,000) can all fly so quickly in such close proximity without hitting each other. ¬†For those of you uninterested in ornithology (the study of birds), there are also plenty of examples of swarms in entomology (the study of insects) and ichthyology (the study of fish), and even¬†chiropterology (study of bats).

Image by SteveD
Image by SteveD

In each case, the animals are unaware (and frankly, uncaring) of the beautiful shapes their swarms make. ¬†They aren’t even trying to swarm. ¬†They are trying to survive and their instinct tells them to follow a few simple rules. ¬†Since the advent of computers, scientists have been trying to find out what those rules are.

One of the most famous computational models of swarming behaviour was proposed by Craig Reynolds in 1986.  In his Boids program, simulated birds had to follow three rules:

  1. Separation:¬†Don’t crash (steer away from nearby boids).
  2. Alignment: Get with the program (steer towards the average heading of nearby boids)
  3. Cohesion:¬†Don’t get lost (steer towards the average location of nearby boids)

This model is actually a really good model for the behaviour we observe in birds and fish.  Recent studies have also shown this alignment rule is especially important for bats.

Locusts, on the other hand, seem to have a much simpler set of rules.  Locusts just want to avoid getting their backsides eaten.  When approached from behind, locusts will tend to fly forward for fear of cannibalism.  This creates an overall tendency to move forward and can lead to giant swarms.

Image by CSIRO
Image by CSIRO

Roundabouts

If you’ve ever been to Swindon (and, from what I hear, you’re not missing much if you haven’t), you might have come across quite possibly the most offensive piece of civil engineering in the UK.

That's right.  A giant roundabout.  Image in the public domain
That’s right. A giant roundabout. Image in the public domain

As a North American, I cringe at the thought of even a tiny roundabout but Swindonians apparently hate everything that is good in this world.

They built the Magic Roundabout. ¬†A terrifying series of 6 small roundabouts encircling a larger roundabout that goes the other way. ¬†If that sounds confusing, it’s because it is.

The more confusing part, however, is that hundreds of thousands of cars pass through it unscathed.  While there is certainly a lot of anxiety about it, there have been only 14 major accidents in 25 years.

Hell for North Americans.  Image from the BBC
Hell for North Americans. Image from the BBC

The vast majority of people pass through fine, despite there being 5 different entry and exit points and many conflict points (places where streams of traffic cross).  This happens because of a few simple rules:

  1. Follow the lines
  2. Give way to cars coming from the right
  3. Drive to where you want to go
  4. Don’t crash

Apparently it’s actually an effective way to move cars through an intersection, but my North American sensibilities just can’t handle it.

For more information on this piece of crazy road engineering, visit this explanatory page and watch this video.

Segregation

Choosing¬†who you associate with based on a singular trait has been known to lead to a lot of issues in the past. ¬†As a dog person, I’ve lost a lot of friends to cats (and their parasites). ¬†Despite my friendly demeanour and my ability to put up with a fairly large proportion of cat-lovers in my immediate vicinity, at a certain point I start to feel uncomfortable and want more fellow dog-lovers.

Tensions flare.  Image by Peretz Partensky
Tensions flare. Image by Peretz Partensky

In 1971, Thomas Schelling set out to model this behaviour and came out with a somewhat surprising and scary result. ¬†Even when people are fine with being in the minority, if they are dissatisfied when surrounded by a large majority of “others”, they will tend towards segregation. ¬†The model followed a few simple¬†rules:

  1. If you are surrounded by a certain percentage (e.g. 30%) of similar people, you are satisfied
  2. If you are surrounded by a certain percentage of different people (e.g. 70%), you are dissatisfied
  3. If you are dissatisfied, move to somewhere where you are satisfied.

Within a few rounds, there is very little diversity left as people¬†tend to move towards those who are similar. ¬†This, despite the fact that no individual is saying they outright dislike the other group or couldn’t live with members of the¬†other group. ¬†This model helps to explain why segregation is so hard to eliminate.

Interestingly, this tendency towards segregation can be reversed if a maximum of similar people rule is added:

4. If you are surrounded by a certain percentage of similar people (e.g. 90%) you are dissatisfied

Again, complex patterns and simple rules.

To learn more about the model, go here.

Conciousness

There are approximately 100 billion neurons in an adult human brain.  These neurons are connected in intricate ways to create an estimated 100 trillion connections.

Now that's a lot of connections!  Image from Wikimedia
Now that’s an impressive set of connections! Image from Wikimedia

Somehow (and to be honest we’re not really sure how yet), these connections lead to all of our brains’ activities from thought to imagination and¬†memory. ¬†The abilities of the system (the brain) couldn’t possibly be known from the rules that neurons abide by. ¬†All that a neuron does is pass on its signal according to a set of rules. ¬†We still don’t know what those rules are.

We do know that when a neuron is activated (whether by electrical or chemical stimulation), it activates other neurons.  The precise number and location of these other neurons is still a big mystery in neuroscience, but it must be activating both nearby neurons and neurons on the other side of the brain.  This dual activation of long- and short-distance connections is what creates the sustained patterns we observe in fMRI scans.

Human Connectome Project
The¬†Human Connectome Project, kind of like the Human Genome Project before it, is setting out to map all of the brain’s 100 trillion connections to better understand how it works. ¬†Image by Xavier Gigandet et al.

While I don’t mean to suggest that everything in life can be boiled down to simple rules, I think it’s pretty incredible the patterns¬†that emerge from individual actors all playing their parts.