The Science of Star Trek: – The Trouble with Tribbles

This is the first in a series of posts exploring the science of Star Trek, courtesy of our friends at the Scouse Science Alliance. In this first post we delve into the real-life biology of everyone’s favorite purring ball of destruction – the Tribble!

parsons1These cute, fluffy, purring balls of joy are considered a mortal enemy of the Klingon Empire (Klingons are a warrior race who love a good battle, and in Kirk’s era they were often the bad guys). They notoriously multiplied uncontrollably on board the USS Enterprise under Captain Kirk in the episode ‘The Trouble with Tribbles’. Starfleet considers them dangerous organisms and forbids them from transport. Despite their purring nature towards humans, the same is not true of Klingons. In fact, Kirk used a Tribble to identify a Klingon in disguise. The Tribble reacted with a screeching noise. Now, how exactly do these fluffy little puffs manage to multiply at such extreme rates? Cleverly, each Tribble is ‘born pregnant’ and if given the smallest morsel of food, will give birth to 10 Tribbles, who in turn will also produce 10 Tribbles. Within hours you have hundreds of Tribbles, clogging up every console, air vent, and food replicator [2].

Is such a creature possible I hear you ask? Well, being a hermaphrodite is nothing new. Snails and plants are examples of this. They possess both male and female reproductive organs, although the female organs of one snail will normally mate with the male organs of another snail, i.e. sexual reproduction. However, in some hermaphrodites self-fertilization can occur [3]. Then there are those species that are able to effectively create clones of themselves via asexual reproduction, such as stick insects. The advantage of asexual reproduction is that it is a relatively quick way to populate an environment, and it does not rely on regular encounters with the opposite sex. It is considered most advantageous in favourable, stable environments. The down side is the inevitable lack of genetic diversity, which would be particularly problematic if conditions became unfavourable. Despite this, some stick insects have been shown to survive for a million years without sexual reproduction, suggesting that this method is genetically sustainable [4].

Therefore, it is very plausible that Tribbles are able to produce offspring in the absence of another Tribble. The only questionable aspect is the sheer speed at which they accomplish this. The shortest gestation period known currently for a mammal on earth is 12 days for the opossum. This animal is a marsupial and whilst it has a very short gestation period, its young are born almost foetal-like and therefore require nursing in the mother’s pouch for an extended period of time before reaching maturity [5]. With regards to Tribbles, not only would their gestation period have to take place in a matter of hours, but the ‘baby’ Tribblewould also have to reach maturity in an equally rapid manner.

If this could actually be achieved, then it would be a huge survival advantage. To be able to maximise breeding potential and minimise the energy intake required tparsons2o do so, is the ambition of all species. What’s more, this rapid production of generations would only serve to increase mutation rates, which in some instances can help species adapt. In fact, much of this can be likened to microbes such as viruses and bacteria. Their rapid succession of generations allows them to adapt much more quickly than us, their human hosts. Therefore Tribbles are merely a victim of their own success. All they want is to eat and breed as efficiently as possible, who doesn’t? So in conclusion, Tribbles are quite like microbes, and microbes aren’t so bad. In fact, they can be quite cute and fluffy too!

SSAThis post, by author Bryony Parsons, was kindly donated by the Scouse Science Alliance and the original text can be found here.

 

 

References

  1. http://www.edparsons.com/2006/03/google-earth-inspiration-was-star-treks-tricorder/
  2. Okuda, M. and Okuda, D. 1997. The Star Trek Encyclopaedia, a reference guide to the future. Updated and expanded edition. POCKET BOOKS, USA. P 522.
  3. Campbell, N. A. and Reece, J. B. Biology, sixth edition. Pearson Education, Inc, USA. P 975-978.
  4.  http://www.bbc.co.uk/nature/14122050
  5. http://www.opossumsocietyus.org/opossum_reproduction_and_life_cycle.htm

The best laid plans o’mice and researchers: my top 5 chance scientific discoveries.

Most scientists are rarely content until they can say that they have planned for all eventualities. But no matter how hard you try, lab work will often throw you a curve ball, turning up all manner of unexpected curiosities. Yes, it’s true the “best laid plans o’mice and researchers gang aft a gley”*! However, there is no need to despair, for buried in the annals of scientific literature are a number of compelling tales where odd results and downright stupidity have actually lead to some pretty ground-breaking discoveries. So, here are five of my favorite examples of scientific serendipity.

5) The artificial pacemaker:

The first implantable pacemaker
The first implantable pacemaker

The first implantable pacemaker was invented and developed by electrical engineer and prolific inventor Wilson Greatbatch. But this is no ordinary tale of academic prowess. Unfortunate and clumsy scientists can take heart to learn that, despite Greatbatch’s impressive academic repertoire, it was actually a technical mistake which lead him towards this life-saving invention.

In 1956, Greatbatch was working on a device to record heart-rhythms when he accidentally connected an incorrect electrical component (for the geeky this was an ill-fitting resistor). This mistake meant that his device actually emitted electrical activity instead of recording it.  Greatbatch worked on miniaturising and testing his creation and by 1960 the first artificial pacemaker was implanted into a human patient. The recipient, a 77  year old man  went on to live for a further 18 months.

This is a great example of when a technical error actually translated into a ground-breaking discovery. But be careful, 99% of the time such mistakes are still significantly more likely to end in blown fuses and angry screaming than medical breakthroughs!

4) The discovery of penicillin.

Alexander Fleming
Alexander Fleming

No list of accidental scientific discoveries could be complete without the tale of Alexander Fleming’s discovery of penicillin. Fleming, who at the time was described as a careless lab technician (charming), returned from holiday to find that one of his badly tended experiments had grown mould. Although in this instance, his inability to maintain a sterile work environment actually revolutionised modern medicine.

Fleming noticed that the Staphylococcus bacteria  in this particular sample did not grow around the mould. Indeed he noted that the Staphylococcus colonies became transparent and were obviously dying.  The mould was soon identified as a rare strain of Penicillium notatum, which appeared to secrete a compound capable of stopping bacterial growth. In fact Fleming’s mucky lab practices had lead him to stumble upon the first known antibiotic – a discovery which has since changed the course of medicine and allowed for previously life-threatening diseases to be completely curable.

Fleming himself is quoted as saying: “One sometimes finds what one is not looking for. When I woke up just after dawn on Sept. 28, 1928, I certainly didn’t plan to revolutionize all medicine by discovering the world’s first antibiotic, or bacteria killer. But I guess that was exactly what I did” (he was obviously a humble chap).

3) Cosmic background radiation.

IMGP0003Any scientist can tell you how annoying inconsistent or noisy data can be, but not many could boast that noise actually won them a Nobel Prize.

In 1965, Arno A. Penzias and Robert W. Wilson were working for Bell Laboratories using a sensitive horn antenna to detect low levels of microwave radiation. As they scanned the sky with this device their findings were constantly overshadowed by a low level of background “noise”. Both scientists assumed that this persistent “noise” was an unwanted artifact and tried a huge range of techniques to eliminate it but their attempts were to no avail. However, after much head-scratching they finally discovered that another group of scientists from Princeton had already predicted that such “noise” should be detectable as a remnant from the Big Bang and were about to start looking for this themselves.

So it turned out that the annoying artifact that Penzias and Wilson spent so much time trying to eliminate was actually background radiation left over from the Big BangIf only experimental noise was always this interesting!

2) Drunk scientists discover wine improves super conductance

A wine label only a scientist could love!Contrary to the popular mathematician’s saying ‘don’t drink and derive’, it seems that, in some cases, a little bit of alcohol (or perhaps a lot) can actually facilitate scientific discovery.

A few years ago, scientists at Japan’s National Institute for Materials Science got a little bit tipsy at an office party and, instead of stealing office supplies, they decided to head back to the lab and do a few unauthorised experiments.

Their lab was working to develop a new type of superconductor by soaking a compound in hot water and ethanol for several hours. But, after a few drinks, one bright spark decided that it would be much more fun to see what happened when they instead soaked this compound in whatever left-over booze they could find from the party.

Amazingly the next morning, alongside the customary hangover, the researchers also discovered that commercially available alcohol seemed significantly better at improving super conductance than anything they would commonly use in the lab. Indeed, using lab- grade ethanol improved the material’s superconductivity by about 15%, while red wine improved it by almost 65%. These results were certainly not expected but were, without doubt, a big step forward for these scientists – I think it may be time for another party!

1) Common worming tablet inhibits growth of cancer cells.

3667927147_e452ddc04eScientists from Johns Hopkins University’s East Baltimore medical campus were left scratching their heads a few years ago when techniques used to grow tumors in mice failed to work on one particular group of research animals. After a number of failed attempts, the researchers decided that there was something kooky about these mice and set about finding what it was.

It turned out that these specific mice had been treated with a cheap, mass-produced, medication used to prevent pinworm infections and that this had been preventing tumor growth in these animals. Spurred on by this unexpected breakthrough, researchers soon found that a related drug – mebendazole – was particularly effective at treating an aggressive type of brain tumor (glioblastoma multiforme).

Years down the line and new drugs, stemming from this unexpected discovery, are now being trialed on terminally ill cancer patients with the hope that this will lead to more widespread use.

So there you have it. If you want to be a top-notch scientist remember that keeping your workspace sterile is totally overrated, regular office parties are a must and don’t forget to love your noise – you never know where it may lead you.

Post by: Sarah Fox
*Often go awry.

Heretic to hero: Sir Harold Ridley and his sight-saving invention

It’s a strange phenomenon that some of the most revolutionarily successful people are initially rejected, scorned or unappreciated. Galileo, van Gogh, Darwin, Lovelace, Mendel and Austen were all vastly unpopular in their time, yet now we all take their scientific and creative contributions for granted. Sir Harold Ridley, the inventor of the intraocular lens, is another example of these late-sung heroes. His work saves the eyesight of millions of people across the world every year, but at first his idea of placing a plastic lens onto the surface of the eye was thought by peers to be impossible, laughable and even dangerous.

Cataract in a human eye. The pupil looks milky or cloudy. Image from Rajesh Ahuja, MD, Wikicommons.

The eyeball acts like a camera: light from the outside travels through the pupil and the lens to focus on the back of the eye, where the light is translated into images by light-sensitive cells that are located there. Due to age, trauma, toxic chemicals or certain diseases such as rubella or diabetes, the proteins that make up the lens denature and become opaque which prevents light from entering the eye and causes cataracts. People with cataracts suffer from very poor vision or blindness (see the image comparison); over half the world’s blindness (around 20 million people) is caused by age-related cataracts alone.

Normal vision. Image from National Eye Institute, NIH, Wikicommons.
Sight with cataracts: the image is blurry or out of focus, . Image from National Eye Institute, NIH, Wikicommons.

 

 

 

 

 

 

 

Over the course of history, several gory approaches to treating cataracts have been trialled. Somewhere between 2000-600BC, a procedure called ‘couching’ was used. This procedure involved using a sharp instrument, or just blunt pressure, to detach the cataract-riddled lens from where it normally resides into the back of the eye. Not surprisingly, this procedure was usually massively unsuccessful: patients usually suffered pain (as this was before a lot of modern anaesthetics were available), inflammation, infection and even blindness as a result. Even if the procedure and aftercare went smoothly, the patient was still left with inadequate eyesight. Unfortunately, couching is still performed in some developing countries where access to healthcare is often restricted.

As general surgical practice improved over the centuries, better tools and instruments were developed that allowed the opaque lens to be either removed, or broken up into small, more easily absorbable pieces. More often than not, patients were still left with poor eyesight and had to wear cumbersome, thick glasses to compensate for the missing lens.

Gordon Cleaver flew a Hurricane, the windshield of which was made from Perspex. Image from Tony Hisget, Wikicommons

Dr Harold Ridley, a recently trained medical doctor who specialised in ophthalmology, worked in the south of England during the Second World War. In August 1940, Flight Lieutenant Gordon ‘Mouse’ Cleaver forgot to put on his flight goggles before going out in his plane for what was to be Adlertag (Eagle Day) – the first day of Luftwaffe’s mission to eliminate the Royal Air Force from the sky. On returning to base, a bullet went through the side of Cleaver’s cockpit and shattered the Perspex window, a small fragment of which entered his eye. Cleaver had many operations on his face to treat the damage, but Dr Harold Ridley’s operation was to change medical history.

When Ridley removed the Perspex from Cleaver’s eye, he observed that there was no inflammation: the body hadn’t recognised the material as ‘foreign’ and so hadn’t initiated an immune response against it (as it usually does against materials like wood or metal). Ridley started thinking: if you could take the Perspex out of eye and there was no inflammation, then there would surely be no biological reason why you couldn’t put it back in.

A modern intracoular lens. The two arms help to fix the lens in place within the eye. Image from Wikicommons.

With this in mind, Ridley developed the first intraocular lens (IOL) – a small disc made from Perspex – and in 1949 placed it into the eye of his patient after first removing her cataract. With further modifications to improve the IOL’s power (that is, the ability of the lens to bend light, as glasses do), some of his first patients even attained 20/20 vision. Initially, Ridley sought to keep his patients’ implants a secret from the academic community until he could confirm from follow-up checks that there were no adverse effects, but a patient accidentally let slip the secret. So, in 1951 Ridley published his results and took two of his patients to be inspected by the Oxford Ophthalmological Congress. His work was rejected by other eye experts and deemed heretic. As a result, Ridley became a professional pariah and sank into depression.

Actor Robert Young had an IOL implanted that allowed him to carry on working. Image from Wikicommons

But not everyone was so sceptical about the IOL. Foreign eye doctors saw the promise of the invention and in 1974  – 25 years after the first IOL implant – a Club was started with the aim of discussing the use of IOLs in cataract surgery. Robert Young, a famous American actor, underwent the procedure and sang its praises to the press. Only years after he retired in 1971 was Harold Ridley officially recognised by the ophthalmic societies and institutions. In 2000 he was knighted by Queen Elizabeth, but he passed away in 2001.

The long-unappreciated work of Harold Ridley is now recognised as not just an invaluable contribution to ophthalmic medicine, but also one of the first ever feats of bioengineering. Applying a scientific strategy such as using materials that are foreign to the body to fix a medical problem was previously unheard of, yet today we benefit from IOLs, dental implants and pacemakers to name just a few. Increasingly, bioengineering takes advantage of 3D printing and other advancing technologies and materials in the production of tissue grafts and implants that, like IOLs, will make such a huge difference to peoples’ lives.

A plaque commemorating Sir Harold Ridley’s achievement at St. Thomas’ Hospital, London. Image from Wikicommons.

Post by Natasha Bray

 

The evolutionary quirks of Australian animals

800px-Reliefmap_of_AustraliaAustralia is home to many interesting phenomena, amongst them its weird and wonderful wildlife. 86% of plants, 84% of mammals and 45% of birds found in Australia are not seen anywhere else in the world.

Australia became separated from the rest of the world when it broke away from Antarctica between 85 and 30 million years ago. The isolation of Australia, combined with its harsh, arid climate has allowed for the evolution of unique species, each filling a particular ecological niche.

Australia’s unique flora and fauna make it one of most fascinating places in the world to biology. The following is a highly scientific* ranking of some of the extraordinary creatures found in Australia, and why they are fascinating to science**.

#5 : The Kangaroo

kangaroo
Credit: Louise Walker

Kangaroos are marsupials, meaning that the females have a pouch in which they will rear the baby kangaroo (joey). Marsupials are also found in North and South America, but are most abundant in Australia.

Famous for using their very strong hind legs to bounce across the Australian plains, the kangaroo and its smaller relative the wallaby use this bouncing to travel great distances, allowing them to survive in the harsh desert conditions of their home country.

There are many different species of kangaroo. The largest, the Red Kangaroo, can grow up to 6 ft 7 in tall.

There’s a persistent rumour that kangaroos are so named because the first Western explorers asked the native Aborigines what those bouncing things were, and the Aborigine replied with their word for “I don’t know”, this being “Can-ga-roo”. However, this is not true, the word “kangaroo” actually derives from “gangurru”, the native word for a Grey Kangaroo.

#4 : The Koala

koala
Credit: Louise Walker

Another famous Aussie native, the koala is found on the east coast. Despite appearances and the fact that it is sometimes called a “koala bear”, it is not a bear at all. It is a marsupial and, like the kangaroo, rears its young (also called a joey) in a pouch.

Koalas famously subsist on nothing but eucalyptus leaves which makes them very slow and lazy. Some people believe that the eucalyptus has a narcotic-like effect on the koalas, a bit like being stoned. But the koalas’ sedentary lifestyle is actually due to a lack of nutrition in its diet leaves; meaning that digestion takes up a lot of energy leaving very little left over for things like moving. With regard to its picky eating habits, the koala may seem a little like its non-cousin the panda, in that they both spend all day eating something which isn’t actually very nutritious. The major difference is that koalas are voracious breeders. When the male is ready to mate, he makes a noise which has been likened to “a pig on a motorcycle”.

As you can see from the picture, koalas have two opposable thumbs. This allows them to climb trees and grab small branches with ease. A recent paper has also detailed that koalas adopt their famous “tree hugging” pose to help them lose body heat.

#3 : The Little Penguin

penguin
Credit: Fir0002/Flagstaffotos, commons.wikimedia,org

The smallest breed of penguin in the world, the Little Penguin stands at 30-35 cm in height. Found only in Australia and New Zealand, these penguins famously participate in the “penguin parade” on Phillip Island, near Melbourne. The penguins spend up to a month at sea feeding, but some will return to their nests at dusk, often to feed their hungry chicks.

When the time comes to return from the sea, the little penguins have evolved a great survival technique – they form groups of 10-20 in the sea, then choose one unfortunate penguin who has to make sure the coast is clear. This scout penguin runs up and down the beach a few times to make sure there are no predators so that the other birds can return safely to their nests.

For more information on the little penguin colony on Phillip Island, Victoria, see this link.

#2 : The Inland Taipan

Photo credit: Bjoertvedt, commons.wikimedia.org
Credit: Bjoertvedt, commons.wikimedia.org

This snake gets the honour of being ranked number 2 because it is the most venomous snake in a country full of venomous snakes – which I think is quite a feat.

The title of “most venomous snake” was awarded to the Inland Taipan as its venom has the lowest LD50 score when tested in mice. This means that a very small amount of toxin is needed to cause death in 50% of subjects when compared to venom from other snakes. The Inland Taipan is also highly venomous when used on human heart cells in culture. One drop of venom is enough to kill 100 men.

Despite its highly venomous nature, the Inland Taipan is actually quite placid and rarely attacks humans. The world’s second most venomous snake, the eastern (or common) brown snake is generally more aggressive and has more fatalities to its name, according to this rather baffling Wikipedia list.

Although it is the most venomous snake in the world, the Inland Taipan is not the most venomous animal in the world. This honour is usually bestowed on the Box Jellyfish. Guess which country this comes from ….

Perhaps the need to be tough enough to survive Australia’s harsh environment may explain why the country contains an abnormally large amount of deadly creatures.

#1 : The Platypus

Credit: John Lewin, commons.wikimedia.org
Credit: John Lewin, commons.wikimedia.org

When the platypus was first discovered by early Western explorers, the scientists back home thought this duck-billed, beaver-like, egg laying creature was a hoax. The platypus and the hedgehog-like echidna (also Australian) are the only living examples of monotremes, or egg laying mammal. They are classed as mammals because they lactate and are warm-blooded (although actually their blood is cooler than most mammals).

Sequencing of the platypus genome in 2008 revealed that it shares genetic characteristics with birds and reptiles along with mammals. Because of this finding, monotremes are believed to have formed a separate branch on the evolutionary tree, very early into the evolution of mammals. This makes the monotremes especially fascinating to science because they give us clues about our evolution that no other animals can.

The reason that the platypus gets top ranking (as opposed to fellow monotreme the echidna) is the extra evolutionary level the platypus brings – the males have a venomous spur on their ankles which can cause severe pain and swelling in humans. This spur is believed to be used during fights between males for the attention of a female.

So there’s your number one weird Australian animal – frankly, what’s not to love about a furry mammalian bird-reptile which, when angered, will give you a nasty kick with its poisonous ankle?

*by “scientific” I mean “in my opinion”.

** this does not include the many varieties of spiders found in Australia for no other reason than I don’t want scary spider pictures on my blog.

Post by: Louise Walker

Can a brain scan reveal your true age?

TWOFor as long as carnivals and funfairs have been around, there have been people who try to guess your age; a trick that often goes hand-in-hand with horror at the response. With our ageing population, which is most likely due to advances in medicines, treatments and our understanding of diseases, age is quite topical.

A recent study has shown that observing  the anatomy of your brain may be able to uncover your true age. A set of biological markers has been shown to accurately predict the age of a young person’s brain. So, if you have ever told a white lie about your age at the cinema to get a child’s ticket, or if you ever tried to trick shop owners into thinking you were 18 so that you could be served alcohol or cigarettes then this could soon be a thing of the past!

Previous studies have tried to observe aspects of brain structure and function with the aim of identifying whether there are common patterns and timings during the development of our brains. Although many studies have been unsuccessful in trying to show this, a study carried out by Timothy Brown at the University of California combined a range of parameters regarding the structure of the brain in order to assess its age. Using 885 subjects aged between 3 and 20 years, individuals were selected from a diverse range of races, educational backgrounds and economic statuses.

Children can develop – in terms of mental capability and maturity – unpredictably, but what is not known is the extent to which these differences are based on physical features of their brain, and or are due to psychology or environment.

Magnetic resonance imaging (MRI) was performed on each of the subjects to look at the internal structure of brains, of which 231 features were studied, including certain structures, the connectivity between different regions, and thickness or volume of different areas of the brain.

oNELarge variations in many of the measurements were observed that corresponded to the ages of the subjects. By combining the data from each of the measurements using a complex mathematical equation, an accurate ‘snap-shot’ of how the brain appears at each age during development was formed.  Although there were slight differences during development between brains of a similar age, the equation was able to correctly predict the age of a child to within a year, with an accuracy of 92%.

These findings indicate the presence of a developmental clock within our brain that produces a precisely timed development of brain structures throughout childhood.

Although these findings are incredibly interesting, aside from giving us insight into how our brains work you may be wondering what the relevance of these findings are. Whether we would be able to use the same technique to reliably determine the age of an adult by looking at the structure of their brain is another question. To be able to identify the true age of an individual has many advantages, but one of the most important clinical applications of this would be in observing whether a child’s brain is developing at a rate that is comparable to others of a similar age. It would also be useful in observing brain structures in individuals with autism, and other developmentally related disorders.

There are also non-clinical applications for this technique, such as cases where border staff need to be able to accurately determine the age of an individual without documents to be able to make a decision on whether to grant asylum. In the Olympic Games in Beijing in 2008, controversy arose when officials were unable to decide whether some of the competing athletes had entered the games illegally by lying about their age in order to compete.

To further this work, the study should address whether the anatomy of the brain is able to reliably predict age in subjects that have reached adulthood. If biomarkers are able to accurately predict our age even after development, then this could lead to rapid advances in the development of medicines for age and development-related illnesses.

Study: Neuroanatomical assessment of biological maturity – Timothy Brown et al. – Current Biology, September 2012.

Post by  Sam Lawrence