Ep 164: The Pod - Flesh eating sea lice

I have started a new podcast called The Pod - I'd love you to have a listen and tell me what you think! Mr Science Show is not gone though, it will continue on boldly!

The Pod is about ocean swimming - there is more to ocean swimming than swimming in the ocean - and will cover a whole spectrum of topics. It is likely to be a very sciencey show!

So here's Episode One, which is a science-based episode on flesh-eating sea lice. For more information, please check out the notes over on The Pod.

Ep 159: Wedding cost, marriage success and cats

From a recent chat with ABC Central West, this week is definitely a correlation of the week. Two separate stories on the topic of love and attachment highlight a couple of statistical concerns you need to be wary of when drawing conclusions from research:

1. The correlation of wedding / engagement ring cost and marriage longevity (concern: correlation does not necessarily equal causation);
2. Does your cat really love you? (concern: sample size)

Listen in below or on the mp3 (and all credit again to ABC and Kia).




References:

• Francis-Tan, A., & Mialon, H. (2015). A DIAMOND IS FOREVER” AND OTHER FAIRY TALES: THE RELATIONSHIP BETWEEN WEDDING EXPENSES AND MARRIAGE DURATION Economic Inquiry, 53 (4), 1919-1930 DOI: 10.1111/ecin.12206  
• Potter A, & Mills DS (2015). Domestic Cats (Felis silvestris catus) Do Not Show Signs of Secure Attachment to Their Owners. PloS one, 10 (9) PMID: 26332470

Ep 152: Spiderman Part 2

In part 2 of the Spiderman series, Dr Boob looks at the amazing properties of spider silk and how Peter Parker might harness various technologies to appropriately use it.

It's the final show from Dr Boob for a while and we will miss him greatly! But he's not disappearing completely - show him you care over on twitter - @doctor_boob

Tune in to this episode here.



Cover by Nippoten
Songs in this episode:

Hebber Zepherin / CC BY-NC 3.0

Loveshadow / CC BY-NC 3.0

Ep 140: The Redback Spider invasion of New Zealand

Research published in Biological Invasions shows that Australian redback spiders are invading New Zealand and could become established in many urban areas around major ports.

The paper, The invasive Australian redback spider, Latrodectus hasseltii Thorell 1870 (Araneae: Theridiidae): current and potential distributions, and likely impacts, details recorded sightings of redback spiders in New Zealand, then used biological and climatic information to reveal where redbacks could establish. Warm, dry conditions in some eastern areas of New Zealand are suitable for redback spiders to become established, and they are likely to spread further as they are surviving in places with relatively high rainfall. Urban areas, for example, provide shelter from the rain. The spread of redbacks is likely to have arisen from the establishment of new invasions through New Zealand's ports.

There is genetic evidence that redbacks have interbred with the protected, endemic katipo and there is a danger that redbacks could competitively displace katipo or cause extinction by interbreeding. Redbacks are also a public health issue as they have the potential to become established in areas close to urban populations. Successful border control already produces regular interceptions of the redback as well the invasive brown widow and the western black widow. Both these species are related to the redback and have similar habitat and climate requirements.

I spoke to lead researcher Dr Cor Vink about this work and how they are developing new approaches and tools to ensure harmful organisms are kept out of New Zealand.

Click play below or listen to this show here.



References:
Cor J. Vink, José G. B. Derraik, Craig B. Phillips, & Phil J. Sirvid (2010). The invasive Australian redback spider, Latrodectus hasseltii Thorell 1870 (Araneae: Theridiidae): current and potential distributions, and likely impacts. Biological Invasions

Ep 137: Can your environment change your DNA?

Did you know that worker bees and queen bees have exactly the same DNA?

Although they look and behave differently, at birth they have the same genome. Young queen larvae are fed a diet of Royal Jelly, a substance secreted by the worker bees which includes B-complex vitamins, proteins, sugars and fatty acids. It also contains trace minerals, enzymes, antibacterial and antibiotic components, and vitamin C. This concoction not only feeds the queen bees, it turns on and off various genes with what are known as epigenetic effects. Epigenetic effects - meaning "above the genome" - alter gene expression without affecting the baseline genetic code. They are the reason why cells in different parts of the body do different things. For example, liver genes are turned on in your liver but not elsewhere, even though every cell in your body contains all your DNA information. For humans, much of this happens when we are embryos before we are born, with various chemical signals switching on and off genes in various parts of the body.

The recent report The Honey Bee Epigenomes: Differential Methylation of Brain DNA in Queens and Workers, by Professor Ryszard Maleszka from The Australian National University’s College of Medicine, Biology and Environment and colleagues, details the extensive molecular differences in over 550 genes in the brains of worker and queen bees as a result of queen bee feeding with royal jelly.

The work is quite profound as it is a step towards understanding how our environment can change our DNA. There is a growing body of evidence that suggests some epigenetic traits may be passed on to following generations rather than just affecting the individual, and this could drastically change our understanding of the process of evolution. The work also has implications for the nature vs. nurture debate, if indeed our nurture can actually change our DNA - that is, our nature.

I had a fascinating chat to Ryszard about this study, the future of this work and his opinions on how this may change our understanding of evolution. Listen in to this show here (or press play below):




Please excuse the noise in the recording of the phone call.

References:
Lyko F, Foret S, Kucharski R, Wolf S, Falckenhayn C, & Maleszka R (2010). The honey bee epigenomes: differential methylation of brain DNA in queens and workers. PLoS biology, 8 (11) PMID: 21072239

Is the Taliban training monkeys to fight in Afghanistan?

Sometimes you gotta love the internets. A story recently popped up that the Taliban was training combat monkeys to fight wars in Afghanistan. The original popped up on the Chinese People's Daily Online (I caught this story on news.com.au) and opened with:

Afghanistan's Taliban insurgents are training monkeys to use weapons to attack American troops, according to a recent report by a British-based media agency.

It doesn't actually identify the British-based agency, but continues:

Reporters from the media agency spotted and took photos of a few "monkey soldiers" holding AK-47 rifles and Bren light machine guns in the Waziristan tribal region near the border between Pakistan and Afghanistan.... According to the report, American military experts call them "monkey terrorists." ... The emergence of "monkey soldiers" is the result of asymmetrical warfare. The United States launched the war in Afghanistan using the world's most advanced weapons such as highly-intelligent robots to detect bombs on roadsides and unmanned aerial vehicles to attack major Taliban targets. In response, the Taliban forces have tried any possible means and figured out a method to train monkeys as "replacement killers" against American troops. 

The report suggests that the monkey killers will arouse Western animal protectionists to pressure their governments to withdraw troops from Afghanistan and that the CIA trained monkeys to kill in the Vietnam War.

What a wonderfully weird, and bogus, story!



The photo of the terrorist monkey at the heart of this story (above) was found by Jeff Schogol at stripes.com to be photoshopped and Live Science went out and asked some actual scientists (gasp!) whether monkey terrorists were possible - they said no...

You can watch CNN's video of the saga here, view some pretty funny comments and images over at fark, but for the best coverage, check out the Taiwan Animated News version below. I can't understand a word of it, but you really don't need to. Make sure you stick it out till the hilarious animation.

Ep 132: Science of Superheroes - The Hulk

The science of superheroes is taking a green and nasty turn this week as we discuss the largest superhero of them all, The Hulk. Join myself and our regular superhero expert Dr Boob as we delve into the science of how we might realise The Hulk in the lab. It was one of the more entertaining interviews I have done for the podcast.

Listen in to this show here (or press play below), and read further for more info:



The Hulk is alter-ego of Dr Bruce Banner, who allegedly bares a striking resemblance to Dr Boob. Banner is a reserved physicist who involuntarily transforms into The Hulk when triggered by a strong emotion such as anger, fear, terror or grief. The Hulk himself is a massive green monster who gets stronger the angrier he gets. He also has bullet-proof skin.

The Hulk’s origin story includes depends on whether we are looking at the comic book Hulk, the Hulk of the two recent movies, or The Incredible Hulk of the TV series (in which it is David Banner, not Bruce Banner, who metamorphoses into The Hulk).

The 2003 movie version "Hulk" includes many of the topics we discuss in the podcast. The movie starts with genetics researcher David Banner – Bruce Banner’s father - working with the military to "improve" human DNA. The opening credit sequence depicts experiments with jellyfish and starfish DNA, and Banner’s notepad mentions bioluminescence. This suggests that the Hulk gets his green colour from jellyfish DNA as some jellyfish bioluminesce at around 450 nm, which is at the blue/green end of the spectrum. In 1961, Osamu Shimomura extracted green fluorescent protein and another bioluminescent protein, called aequorin, from Aequorea victoria while studying bioluminescence. He eventually received the Nobel prize in Chemistry in 2008 for this work. The mention of starfish is also interesting because, as we found with Wolverine, starfish and sea cucumbers have great healing powers and are able to regenerate lost limbs. Evidently, Banner wanted to splice bioluminescence and improved healing into human DNA.

Banner’s experiments then moved to lizards and monkeys, but unfortunately they all died. Naturally, he then decided if his experiments did not work on animals, he would try them on himself – clearly, ethics committees are not part of superhero science. After conducting experiments on his own DNA, he eventually passes on his mutant DNA to his unborn son Bruce. Once David realises this, he changes his approach and works to cure his son of his genetic afflictions, however the research is shut down and an explosion kills David’s wife. David is taken to a lunatic asylum and Bruce is adopted.

Years later, Bruce has followed his father’s line of work and is conducting military research – Bruce’s area of interest is the use of nanomeds in soldiers. This might include such things as targeted drug delivery for rapid recovery from injury. An experimental accident subjects Bruce to an enormous dose of gamma radiation which “activates” his mutant DNA (possibly combining with the nanomeds) and the building rage/stress transforms him into The Hulk for the first time.

Whether or not this is scientifically possible – well, that’s the topic of the podcast so tune in!

Other issues that we discuss include:

• Gamma radiation and radiation poisoning;
• Genetic transfer and gene therapy – could David Banner change his own DNA in such a way that this change would be copied to his progeny? For more information, check out the Weismann Barrier;
• The Hulk’s size – is it possible to rapidly increase your size? Simple conservation of mass equations would suggest no, and bacteria in a Petri dish generally have a 24 hour doubling time. There are also enormous metabolic requirements involved – we need to have resources available to feed these growing cells and Bruce Banner is not excessively fat. Perhaps to do this we need to accelerate Bruce Banner to the near the speed of light, at which point he may relativistically pick up some mass - however, this is not particularly practical!
• The Hulk’s strength – is it possible to rapidly increase your strength?
• The Hulk's healing properties - could we use some of the science of Wolverine here?
• The materials used to create bullet-proof skin. The toughest skins in the animal kingdom are crocodile, elephant, shark and armadillo; however none are bullet (and knife) proof;
• What materials could we use to make his "one-size-fits-all" pants? You will notice that no matter what size Bruce Banner or The Hulk are, and no matter what the ripped state of his other clothes, his undies always fit.
• And of course, whether The Hulk has irritable bowel syndrome and wears giant green snuggies.

Hope you enjoy this show - we certainly enjoyed recording it, as you will be able to tell by the end! Listen in to this show here (or press play below):



NB: I've now discovered there's a Red Hulk - future show perhaps?
Samples in this podcast are broadcast courtesy of ioda PROMONET. They were:

The Toxic Avenger "Superheros 2007"  from "Superheroes"  Buy at iTunes

Spaceman "Superhero" from "Little Baby Souls" Buy at iTunes

Candye Kane "Superhero"  from "Superhero"   Buy at iTunes

Ninja Kodou "Superhero (Psychedelic Man)" from "Ninjutsu"   Buy at iTunes

References:
Shimomura, O., Johnson, F., & Saiga, Y. (1962). Extraction, Purification and Properties of Aequorin, a Bioluminescent Protein from the Luminous Hydromedusan,Aequorea Journal of Cellular and Comparative Physiology, 59 (3), 223-239 DOI: 10.1002/jcp.1030590302

Moghimi, S. (2005). Nanomedicine: current status and future prospects The FASEB Journal, 19 (3), 311-330 DOI: 10.1096/fj.04-2747rev

An egg in space - or an egg in a vacuum - what would happen?

This is a question that has been bugging us at work.

What would happen to a chicken egg in space? Equally interesting is the question what would happen to a chicken egg if placed in a vacuum chamber?

Eggshells are able to withstand quite large forces from the outside because of their dome structure, but are not so strong from the inside. This makes sense - they need to be strong enough to withstand the force of the mother chook sitting on them, but need to be fragile enough from the inside for the baby chick to escape. If placed into a vacuum, would the pressure of the small amount of air inside the egg be enough to break the shell? Let's assume for the sake of argument that the egg was laid at normal atmospheric pressure.

Other things to consider include temperature. Would the egg white and egg yolk freeze and therefore expand? This could break the shell. Is there enough empty space inside the egg into which the mainly water interior could expand? Or would this happen too suddenly? Is temperature actually a factor?

Or perhaps a sudden change in pressure might cause the interior to rapidly boil, exploding the egg? Water only boils at 100 degrees at normal atmospheric pressure - the more you lower the pressure, the lower the temperature that water boils at. For instance, at the top of Mount Everest, the boiling point of water is 69 degrees. Human blood would boil in space except for the fact that our skin is strong enough to protect our blood from the rapid drop in pressure. Is an eggshell similarly strong, or is it too permeable?

Is there a difference between the scenario where the egg is in space - let's say at about the Earth's orbit - and so is heated by the Sun (or at least half of it), and in a vacuum chamber where there is no heat source?

As much as we like to ponder these questions, we don't have an answer. What do you think? Please feel free to speculate and throw ideas into the mix.

For extra reading, check out the references for work conducted on hatching chickens in low gravity, and also hypergravity.

References:
SUDA, T., ABE, E., SHINKI, T., KATAGIRI, T., YAMAGUCHI, A., YOKOSE, S., YOSHIKI, S., HORIKAWA, H., COHEN, G., & YASUGI, S. (1994). The role of gravity in chick embryogenesis FEBS Letters, 340 (1-2), 34-38 DOI: 10.1016/0014-5793(94)80168-1

Jones SM, Warren LE, Shukla R, Browning A, Fuller CA, & Jones TA (2000). The effects of hypergravity and substrate vibration on vestibular function in developing chickens. Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology, 7 (3), 31-44 PMID: 12124183

Ep 129: The domestication of the dog and the Australian dingo

The Australian dingo and the New Guinea Singing Dog may be the world's oldest dog breeds.

The study, Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication, which was published in Nature and is a major genetic study into the domestication of the dog, was a world-wide effort and had 37 authors - including Dr Alan Wilton, of the School of Biotechnology and Biomolecular Sciences at UNSW. The study found that the dingo and the New Guinea Singing Dog are the most closely related breeds of modern dogs to the original wolves from which all dog breeds come from. They are also the most like the original domesticated dog.

The study looked at 48,000 sites in the dog genome in hundreds of wolves, almost a thousand dogs from 85 modern breeds and several ancient dog breeds. Dr Wilton, a celebrated scientist in the field of dingo research and conservation who won the Unsung Hero of Science Award in 2004, provided the dingo DNA. The data suggest most dogs were domesticated in the Middle East around 10,000 years ago, rather than in Asia as had been previously thought.

Dingoes separated from other breeds of dog when brought to Australia around 5,000 years ago. However, they never made it to Tasmania, which became isolated from the mainland around 12,000 years ago. It is thought that the dingo out-competed the thylacine (Tasmanian Tigers) leading to its extinction on the mainland.

Other ancient breeds include Chow-Chow, Basenji, Akita, Chinese Shar-Pei, Siberian husky and Alaskan malamut.

I had a great chat to Dr Wilton about this work into the domestication - or as I repeatedly say, domestification... - of the dog and also about his work in dingo studies and conservation.

To listen to this show, tune in here (or press play below):




References:
vonHoldt, B. (2010). Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication Nature, 464 (7290), 898-902 DOI: 10.1038/nature08837

Ep 127: Conditioning quolls against cane toads

The cane toad in Australia is a text book example of a feral species. As an introduced species, it has no natural predators and out-competes native animals for food and habitat. Things are made worse by the fact that cane toads are highly poisonous - so poisonous that they can kill animals as large as crocodiles.

One species imperilled by the cane toad is the Northern Quoll. The northern quoll has been almost driven to extinction in many parts of northern Australia because they attack the toad and are subsequently poisoned. The poison kills the quolls too quickly for them to learn not to do it again.

In a recent study Conditioned taste aversion enhances the survival of an endangered predator imperilled by a toxic invader in the Journal of Applied Ecology, Stephanie O'Donnell, Jonathan Webb and Richard Shine from the University of Sydney tested whether quolls could be taught to avoid eating cane toads through "conditioned taste aversion" (CTA).

I spoke to Dr Webb about their study and how quolls can possibly be saved from extinction by CTA. To listen to this show, tune in here (or press play below):



Working with the Territory Wildlife Park, the researchers took a group of quolls and taught half (the "toad-smart" group) to associate eating a cane toad with feeling sick by feeding them a small dead cane toad laced with thiabendazole. The cane toad was too small to kill the quolls with its poison, however the tiabendazole made them feel sick. The second half of the quoll group ("toad-naive") were not fed the cane toad.

The next part of the experiment was to feed the quolls a small, live cane toad in plastic container to see whether or not they attacked it. It was found that the toad-smart group was less likely to attack the toad in the plastic container. See the video below to catch this behaviour in action. It was also found that the toad-smart group survived up to five times longer in the wild than "toad-naive" quolls. The researchers also found that male quolls were far more likely than female quolls to attack cane toads. Dr Webb thinks that aerially deployed 'toad baits' ahead of the cane toad invasion front could educate quolls to avoid attacking cane toads before the toads invade.

Cane toads were introduced to Australia from Hawaii in June 1935 to control the native Cane Beetle. They bred immediately in captivity, and by August 1935 more than 102 young toads were released in northern Queensland. Toads now number over 200 million and have steadily expanded through Queensland, reaching the border with New South Wales in 1978 and the Northern Territory in 1984. It is estimated that cane toads migrate at an average of 40 kilometres per year.

More on science daily. To listen to this show, tune in here (or press play below):



The video below (from YouTube) shows the toad-smart quoll leaving the cane toad alone - then knocking over the camera.

Ep 122: Science of Superheroes - Wolverine (Part 2)

This is the second part of our series on the science of Wolverine - specifically, how can we create Wolverine in the lab? Join Dr Boob and myself as we journey through Wolverine's characteristics and how they may be recreated in a human. Read more on Wolverine in part 1 of this series. To listen to this show, tune in here (or press play below):



Specifically in this episode, we tackle the topics of:

1. What would happen to your bones if you completely covered them with metal? Bones are living parts of your body and make red blood cells, platelets and bone marrow - among other things - that are vital for life.
2. Would a lack of platelets reduce Wolverine's ability to heal?
3. Wolverine is likely to be on a cocktail of drugs, including anabolic steroids to beef him up, immunosuppressants so his body doesn't reject the metal coating on his bones, and various drugs to supply red blood cells, bone marrow and platelets.
4. Could we really harness the healing powers of the sea cucumber for Wolverine, and would they work quickly enough?
5. Are carrots enough to improve his sight?
6. What metal could we use to coat his bones? It needs to be able to be injected as a liquid and then harden at body temperature. Most steels have melting points over 1000 degrees Celcius, and this would cause terrible trauma to his body. Dr Boob's suggestion was CerroLOW117, which is 44.7% Bismuth, 22.6% Lead, 8.3% Tin, 5.3% Cadmium and 19.1% Indium. CerroLOW117 has a melting point of 47 degrees Celcius, however lead and cadmium both accumulate in the body and have adverse health effects. It is highly likely CerroLOW117 would not be strong enough to help Wolverine anyway.
7. And what is a phlebotomist?

For more on superheroes, check out our recurring science of superheroes series. And for more from Dr Boob, check out Chris's other contributions.

Ep 121: Science of Superheroes - Wolverine (Part 1)

Wolverine is probably the best known of the X-Men. Commonly known as Logan, Wolverine is a mutant who has animal-keen senses, super bodily strength, retracting claws, and the ability to almost instantly heal himself from injury. And thanks to some evil scientists, he has the near indestructible (and fictional) metal alloy adamantium fused to his bones, meaning that his claws and skeleton are almost unbreakable.

In the second episode of our regular series on the science of superheroes, biochemist Dr Chris Pettigrew (aka Dr Boob) and I discuss where in nature Wolverine's powers can be found, and how we might scientifically create Wolverine in the lab. This is the first of a 2-part show on Wolverine - see below for a brief description of some of the science discussed. Our first superheroes episode was on the science of Wolverine's fellow X-man, and sometime love interest, Mystique.

To listen to this show, tune in here (or press play below):



The name Wolverine comes from the Wolverine animal, which lives in isolated northern areas such as the arctic and alpine regions of Alaska. It is a stocky and strong animal that is very strong for its size and has been known to kill prey as large as moose. The wolverine is not actually a bear or a dog, but rather a mustelid, or in common parlance, a weasel.

While many of Wolverine's powers (such as strength and hearing) could come from its namesake mustelid, if we were to attempt to create Wolverine in the lab, we must first turn to the ocean:

Healing ability:

Sea Cucumbers are the champions of organ regrowth. All animals possess some kind of tissue repair mechanism, however the sea cucumber belongs to a group of animals that can regrow lost limbs - salamandas and some starfish also have this ability. The repair process involves cells called morula cells, which move to the point of injury. Although all animals have wound repair processes, not all can regenerate lost body parts. With the sea cucumber, the same processes that repair its injuries also repair limbs and internal organs, and this opens up the possibility that we could one day discover how to repair our own wounds and perhaps how to regenerate body parts. But as Dr Boob says, we are quite some way off from instant healing ability: "The odd bullet to the head won't be able to be dealt with."

Retractable Claws:

There is a remarkable analogue found in nature for Wolverine's retractable claws. University of Harvard biologists have determined that some African frogs have the ability to puncture their own skin with sharp bones in their toes. These bones then act as claws to attack predators. The defence mechanism was discovered by David C. Blackburn, James Hanken, and Farish A. Jenkins, Jr. Blackburn said, "It's surprising enough to find a frog with claws. The fact that those claws work by cutting through the skin of the frogs' feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality."

Blackburn discovered the frog and its defences when he was conducting fieldwork in Cameroon and one frog he was studying scratched him. He found 11 frog species in the genera Astylosternus, Trichobatracus and Scotobleps who had this peculiar ability. Read more at Project Frog.

Smell, sight, hearing

Whilst there are obvious candidates in nature that have heightened sight, smell and hearing abilities, recent studies suggest that human and dog olfactory receptor genes evolved from a common mammalian ancestor, and as such Dr Boob thinks that mimicking the smelling ability of dogs could be quite "easy." Dogs have an olfactory sense approximately a hundred thousand to a million times more acute than a human's. Scenthounds can smell one- to ten-million times more acutely than a human, and Bloodhounds, ten- to one-hundred-million times more.

To hear more on the science of Wolverine, tune in here (or press play below):



Part 2 of this series on the science of Wolverine will be aired over the next few weeks. The song A Russian Peter was used in the background of this podcast, with permission from Ioda Promonet. Buy the full London Philharmonic Orchestra Peter and the Wolf CD, or download individual songs as mp3s, from Amazon here.

Swimming with Whales - video from Tonga

A few months back, I spoke to Scott Portelli about his experiences diving with whales in Tonga - see Ep 109: Tongan blowholes and whales. Scott has recently returned from Tonga, and took from breathtaking footage of the whales. Enjoy the video below.

Ep 110: Coral, the Stone Henge of the Pacific, and more of the sights, sounds and science of Tonga

This week's podcast takes us back across the ocean to discover more of the sights, sounds and science of Tonga - see our previous episode for more on Tongan blowholes and whales.

On location in Tonga, we tackle the topics of:

1. Haʻamonga ʻa Maui - otherwise known as The Stone Henge of the Pacific. This is an ancient 12-tonne stone trilithon whose purpose is not exactly known, much like that other Stone Henge in the UK. A previous King of Tonga, Tāufaʻāhau Tupou IV, once claimed it had an astronomical significance as it can determine the position of sunrise at solstices and equinoxes. As it was said by the King, it is the accepted explanation for what is an odd stone construction, at least in Tonga anyway.
2. How did people get to Tonga in the first place? The generally accepted history is that the Lapita people came down through Papua New Guinea into Melanesia and Polynesia. However, Norwegian explorer Thor Heyerdahl had other ideas based on the fact that the sweet potato (kumera) is found in both South America and Polynesia. To prove that it was at least possible that Tongans came from South America, in 1947 he sailed the Kon-Tiki raft across the Pacific Ocean from Peru to Tuamotus. Heyerdahl showed that, by using only the materials and technologies available at the time, there were no technical issues that prevented South Americans coming to Polynesia. Whilst the evidence suggests that people came through South East Asia and Papua New Guinea to reach the Pacific, one school of thought suggests that Polynesians may indeed have travelled to South America and picked up the kumera from there.

Back here in Australia, I spoke to Lachlan Whatmore about coral - what is it, how does it form, and what life does it support. Lachlan is a diving enthusiast and the golden tonsils of Australian community radio - as well as a qualified Marine Biologist. In short, coral is an Anthozoan marine organism that lives in colonies of polyps. Corals build reefs in tropical oceans - the reefs are made up of their calcium carbonate skeletons. Listen in for more.

And tacked onto the end of this show, we have a Correlation of the Week - this week discussing the relationship between eclipses and the stock market - see our previous story on the topic for more.

Listen to this podcast here:

Stay tuned for our final edition on Tonga in a few weeks.

Ep 109: Tongan blowholes and whales

The Kingdom of Tonga is an archipelago in the South Pacific Ocean comprising 169 islands stretching over a distance of about 800 kilometres. It is the only sovereign monarchy in the Pacific and takes pride in its claim that it was never colonised.

I recently spent a wonderful two weeks in Tonga - the islands completely live up to their billing as the Friendly Islands - Captain Cook gave Tonga this moniker after his first visit in 1773 when he was treated to various festivals. It was only later that it was revealed local chiefs wanted to kill Cook but could not agree whether to attack by day or night.

This is the first in a series of podcasts about Tonga that include my own recordings from Tonga and also interviews with experts in the scientific areas we tackle. In this show, we look at:

1. The Mapu a Vaea blowholes - these blowholes are created by the ocean pounding into the coastal rock and moving through natural tunnels creating a fountain;
2. Tongan singing - not much science here, but it's beautiful!
3. Whale behaviour and migration - I chat to Scott Portelli, an award winning photographer and diver who runs whale-watching tours in Tonga. Scott recently won the prestigious Scuba Diver AustralAsia - Through the Lens Underwater Photography Competition with an outstanding photo from Tonga - see more of Scott's photos on his webpage. Scott runs Swimming with Gentle Giants, a company which conducts whale diving tours each year between August and October off the islands of Vava'u in northern Tonga. I chat to Scott about:
• his experiences swimming with whales,
• when to swim with whales,
• whale behaviour and migration patterns,
  
• the oceanic animals of Tonga,
  
• a little bit of whaling politics,
• the threats to whales, including whaling, global warming and pollution, and
  
• the fact that I once ate whale...

There are very few places left so get booking if you would like to swim with whales this year.

Stay tuned for more on Tonga in upcoming podcasts, in which we will talk about, and experience, the intoxicating drink Kava, the Stone-Henge of the South Pacific, the effects of global warming and rising sea-levels on Tonga, the local animals and more on whaling science and politics.

Listen to this podcast here:

And see below for some very cool traditional dance (also here if you can't see the video):

Ep 104: Invasion Genetics

Dr Katarina Mikac works in an area of science with a fantastic name - Invasion Genetics.

Invasion Genetics is an area of molecular ecology. Molecular ecology is the study of how organisms interact with their environment from a molecular point of view - that is, it examines the roles of DNA and genetics in how species adapt to their environments. It's also part of the larger field of evolutionary biology which looks at the origins of species and how they evolve over time.

Specifically, invasion genetics tracks the movements of invasive species using their DNA - you can't put tracking devices on insects!

One of Katarina's research areas is the Khapra bettle - the world's most destructive seed-eating pest. The beetle feeds on grain and seed kernels, and can decimate storage systems. In fact, heavy infestations can destroy thousands of kilos of stored grain in a matter of weeks. However, it is not present in Australia and this is where Katarina comes in. Australia plays host to the khapra's sister species, from which it is virtually indistinguishable, but by using DNA fingerprinting, Katarina is aiming to develop a species identification test which could identify the beetle at airports and stop it from coming into the country. Another aim is to investigate the sister beetle's genetic diversity and gene flow in order to understand its distribution and movement patterns. This will lead to better understanding of the consequences of the inadvertent introduction of the khapra beetle.

Katarina's current work is on the population genetics of the invasive Western Corn Rootworm which destroys corn if left untreated. In the United States, it is estimated that 30 million acres of corn (out of 80 million grown) are infested andvthat Corn Rootworms cause $1 billion in lost revenue each year.

In 2007, Katarina won the 2007 Science and Innovation Award for Young People in Agriculture, Fisheries and Forestry for her work on the Khapra bettle and is just about to leave our shores for a series of conferences in Germany and Croatia on the Western Corn Rootworm - good luck Kata!

Listen to his podcast here:

Ep 100: Your Top 10 Science Stories from 2008

With 2008 done and dusted, it is now time to look back and reflect on the science year that was. It is also our 100th podcast episode, so I would like to say thanks very much to all my subscribers, whether you get your Mr Science fix via the podcast, email, in an RSS reader, however you do it, thanks! If you have, by some chance, listened to all 100 episodes, then I'd love to hear from you as not even my parents have listened to them all....

The winner of our 2008 year in science competition is... Dr Steven Farrell from Cork in Ireland. Congratulations Steven! Steven won the random draw for suggesting the Large Hadron Collider as his favourite science story from 2008. Thanks to everyone who entered the competition and suggested stories - each story listed below was entered by at least one person. Steven has won the book The Open Laboratory: The Best Science Writing on Blogs 2008 - the book will be published very shortly and will feature one blog by me - I'll put out a post about this when the book comes out, but in the meantime, check out the 2007 version.

Listen to his podcast here - includes short snippets from the music of 2008, plus a couple of shout-outs from friends of the show (thanks Brains Matter and Jacqui Hayes from Diffusion):



Now to the countdown....

10. Weird Animals

2008 was a year for weird science emanating out of Europe:

• By analysing 308 pastures on Google Earth, German scientists found that cows have an inner compass and align themselves according to the earth’s magnetic field. Red deer and cows orient themselves on a North-South axis, but it is not known why. The researches hypothesise that it may have something to do with health, milk production or with preparation in case the animals are forced to migrate.
  

• The 2008 Ig Nobel Prize in Biology went to French researchers who discovered that fleas living on a dog can jump higher than fleas living on a cat.

9. Weird Research (impacting our sex lives...)

Two bits of weird science that made the news in 2008 will have quite an impact on our sex lives:

• The news that beer goggles are real and that people do look more attractive when we’re drunk really shouldn’t be that much of a surprise;
  

• But the researchers from California who confirmed that the humble roll of sticky tape is a source of x-rays should perhaps concern us. The researchers admit that Soviet scientists had found something along these lines in the 1960's, but still don't know how it works. We should all think twice about wrapping Christmas presents with the tape dispenser close to our nether regions...

8. The Kakeya conjecture

And now for some difficult science, and the work of Zeev Dvir and Australia’s own Terence Tao on the Kakeya conjecture is mind-blowing, if you understand it.

The Kakeya conjecture is part of geometric measure theory and stems from the Kakeya needle problem posed in 1917:

What is the least area in the plane required to continuously rotate a needle of unit length and zero thickness around completely (i.e. by 360 degrees)

For instance, you can rotate a unit needle inside a unit disk, which has area π/4. By using a deltoid one requires only π/8 area. See here for an animation of that rotation.

In 1928, a bloke by the name of Besicovitch showed that in fact you can rotate this needle in an arbitrarily small amount of area – that is, essentially zero area. This seems unintuitive, but is not too difficult to picture. Imagine you have a needle and you slide it along the direction it points for some distance (which costs zero area - remember the needle has zero width). Then turn the needle slightly, which costs a small amount of area, slide it back and turn it slightly again. Then slide up, turn, slide back, turn etc. At each turn you rotate in the opposite direction to the last. If you keep doing this until the needle has completed 360 degrees, the amount of area that has actually been used to turn the needle gets smaller and smaller for smaller and smaller turns at the end of each needle slide. Check out this animation to see this idea in action.

The Kakeya conjecture concerns the fact that you can make this needle turn through arbitrarily small amounts of area, and takes it into higher dimensions (that is, not simply 2 dimensions). Zeev Dvir, who according to Terence Tao produced a “beautifully simple argument”, proved a special case of the conjecture, the finite field Kakeya conjecture.

Perhaps this should have made my mathematics highlights of 2008…



7. The creation of artificial bacteria by Craig Venter

Scientists have discovered a more efficient way of building a synthetic genome that could one day enable them to create artificial life. The method is already being used to help develop next generation biofuels and biochemicals in the labs of controversial US scientist Craig Venter.

Venter has hailed artificial life forms as a potential remedy to illness and global warming, but the prospect is highly controversial and arouses heated debate over its potential ramifications and the ethics of engineering artificial life. The J. Craig Venter Institute succeeded in synthetically reproducing the DNA of a simple bacteria last year.



6. Chandrayaan moon landing by India

India became the first country outside the US and the old USSR to land a spacecraft on the moon. Its lunar orbiting spacecraft Chandrayaan 1 released the Moon Impact Probe, which reached the surface of the Moon on Nov 14 2008. This date was chosen to commemorate the birthday of Jawaharlal Nehru, the first Indian Prime Minister who initiated India's space program. Developed in India by the Indian Space Research Organisation, the MIP had the Indian flag painted on its exterior. Although Japan and Europe had previously commanded their orbiters Hiten and SMART-1 to crash on the Moon's surface at the end of their lifetimes, India's MIP was the first probe designed specifically for a trip to the lunar surface since the Soviet lander Luna 24 in 1976.

The Indian MIP-1 probe did not include braking rockets and was destroyed upon impacting the lunar surface at its planned speed of 3,100 miles per hour.



5. Stem Cell Fraud

One of the less savoury aspects of science is fraud. In 2006, South Korean Hwang Woo-suk fabricated stem-cell results in two academic papers, and in 2008, stem-cell fraud again hit the headlines.

Morayma Reyes, a former member of one of the highest-profile teams in stem-cell biology, was found to have falsified results. In 2007, the work of Catherine Verfaillie and researchers from the University of Minnesota became mired in controversy, after magazine New Scientist pointed to irregularities in their published results. An expert panel was examined and it was found that PhD student Morayma Reyes had falsified data.

The fraud is significant as in 2002, the team published a paper in Nature suggesting that a rare type of adult stem cell from bone marrow could give rise to all of the body's tissues. Such versatility had previously been seen only in embryonic stem cells. This was an astounding result and opened the door to creating cell-lines in a more “ethical” manner than using embryos.



4. The Story of HM

The most moving science story from 2008, and certainly some of the best science writing, comes from the New York Times and concerns the life and death of Henry Gustav Molaison, known as HM.

HM knew his name, that his father’s family came from Louisiana and his mother’s from Ireland. He knew of the 1929 stock market crash and World War II, but not much more. He could not remember anything of his life before 1953, when he underwent an experimental brain operation to correct an epileptic seizure disorder. He emerged from the operation with profound amnesia and had lost the ability to form any new memories.

For the next 55 years of his life to 2008, everything he did, from meeting someone, to going for a walk, eating dinner and watching TV, in his mind, it was the first time he had ever done it. And throughout those 55 years, he was recognised as the most important patient in the history of brain science. He took part in hundreds of studies and contributed immensely to our understanding of learning, memory and what it means to be human. HM died in 2008.



3. Discovery of water ice on Mars

I love the fact that it was a Mars Phoenix twitter status update that confirmed what many of us had always hoped, that there is water ice on Mars.

Water-ice has been found in vast quantities just below the surface across great swathes Mars. Some people are now arguing that NASA should now commit itself to a manned landing within 20 years. The discovery was made by the Mars Odyssey spacecraft and now seems to answer a long-unanswered puzzle, where did all the water on Mars go? We’ve known for a while from valleys on Mars that water once flowed and we used to ask whether all the water evaporated into space because of the lack of atmospheric pressure on the surface. Now it seems it all froze underground. If it all melted, Mars would be completely covered in a planet-wide ocean!

Incidentally, the Mars Phoenix Lander won a Shorty award for twitter its efforts.



2. Climate Change

Climate change will feature in every top 10 of science from now until the year 3000, if we’re still here and writing blogs and recording podcasts - and it's making its third appearance on this blog after topping the 2006 list and coming in 9th in 2007. The hole the in ozone layer was the second largest in history, the Arctic experienced its second smallest cover of ice, and after remaining flat for a decade, methane levels started to rise again.

The Australian government let nearly everyone down with its soft carbon targets, and concerns have mounted over the global production of biofuels which have been grown in place of food crops.

Watch this space, I’m sure climate change will feature again in 2009.



1. The Large Hadron Collider

In the words of Dr Steven Farrell, our competition winner...

I loved the LHC for a couple of great reasons. Firstly, growing up in the age of Bond villains who were intent on gigantic technological pieces capable of destroying the earth, I loved the idea that the collider might possibly generate a black hole and consume the earth thus destroying all evidence of human existence. Awesome. I don't care if any number of physics associations came out and said it wouldn't happen. They couldn't be 100% sure that it wouldn't. Fantastic. And the second reason is obviously that this rather expensive piece of technology that took a fair bit of time to put together broke. And pretty darn quick too. So yeah, that's my highlight.

It cost approximately US$10 billion to build, and almost 20 years to complete, got everyone excited, then it broke. For about week, everyone was an expert on the Higgs boson and fearful that the LHC might create a mini-black hole, which would not only swallow the Earth, but the whole Universe! After a few tests and no black holes, a small fault in one of the magnets caused the LHC to be shutdown. Watch this space in 2009.



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So there you have it, the top 10 science stories from 2008 as contributed by Mr Science Show lovers. Thanks to all who contributed and we'll do it all again next year! Please let me know of any stories you would have liked to have seen - and please write and say hi if you're a long-time listener of the show!

Listen to his podcast here:

Correlation of the Week: Shark attacks and the Global Financial Crisis

We've looked in the past at poor correlations - for instance, it wasn't too difficult to show a relationship between the performance of the Australian cricket team and the price of oil - whilst it looks intriguing, it would be wrong to read anything into it. In this vein, I thought we'd introduce a new recurring award, that of the venerable Correlation of the Week! (Although it probably won't come out weekly...)

This award is dedicated to work proclaiming a cause-and-effect relationship when one probably doesn't exist. Often it's not the fault of the scientists involved - scientists are wont to musing upon possible reasons for their results. No, it's generally the media playing up the story for effect.

A quick reminder of our 3 reasons correlations can occur:

1. There is a direct cause and effect relationship between the two data sets;
2. There is an underlying reason for the two data sets to move together, as opposed to one causing the other;
3. There is no cause and effect and no underlying reason for the correlation - it's simply a coincidence or the work of a devious statistician.

Correlation of the Week deals with the 3rd reason - that is, when there is no cause and effect at all. And the inaugural prize goes to....

Shark Attacks Drop Due to Global Financial Crisis

Reuters recently reported that the number of fatal shark attacks in 2008 dropped from the 2007 result of 71 to 59, and placed the blame (if that's the right term) at the feet of the GFC.

George Burgess, who directs the International Shark Attack File at the University of Florida, said:

"I can't help but think that contributing to that reduction may have been the reticence of some people to take holidays and go to the beach for economic reasons."

This is rather tenuous speculation. There are quite a number of issues involved here:

1. Is the data accurate? Have they captured every fatal shark-attack across the whole world over the last year?
2. Is the decrease simply noise? What about other years? Two data points don't tell us much.
   
3. What other factors are involved? Fishing, oceanography, where the attacks occurred, availability of medical resources, the list goes on. Surely more than economics.

Indeed, the ISAF states many of these things in it's initial report on the topic - which incidentally is a nice summary of the issue. Indeed, they state:

"Year-to-year variability in local economic, social, meteorological and oceanographic conditions also significantly influences the local abundance of sharks and humans in the water and, therefore, the odds of encountering one another. As a result, short-term trends in the number of shark attacks - up or down - must be viewed with caution."

The ISAF prefers to look at the data on a larger time-frame, and when doing that, the data suggests that shark attacks are going up because humans are spending more time in the ocean (a fair conclusion to draw), despite the fact shark numbers are getting smaller.

"Even with the recent levelling trend, the number of unprovoked shark attacks has grown at a steady pace over the past century. Overall, the 1990's had the highest attack total of any decade and the first decade of the 21st century will exceed that total."

The ISAF also notes that it's data could have errors in it, suggesting that the difference between 2007 and 2008 could be noise or data inaccuracy:

"The ISAF's efficiency in discovering and investigating attacks has increased greatly over the past decade, leading to further increases in attack number. Transfer of the ISAF to the Florida Museum of Natural History in 1988 resulted in greatly expanded international coverage of attack incidents and a consequent jump in the number of documented attacks.... Fundamental advances in electronic communication, a greatly expanded network of global ISAF scientific observers, and a rise in interest in sharks throughout the world, spawned in part by increased media attention given to sharks, have promoted more complete documentation of attack incidents in recent years.... Our strong web presence regularly results in the receipt of unsolicited documentation of shark attacks. Many of these attacks likely would have been missed in the past."

So congratulations to the first recipients of Correlation of the Week! The award is brought to you by the Church of The Flying Spaghetti Monster, which blames global warming on the fact that pirate numbers are reducing (and therefore offending TFSM).

So I say to you Reuters and those correlating shark attacks with the economy:

"What would the Flying Spaghetti Monster Do?"