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Past Episodes: March 2012 Archives

Saturday March 31, 2012

* Facing the Truth * Revealing Raindrops * Evolution Doping * Madagascar's Founding Mothers * Hyper Planets * Fact or Fiction - Robins and Worms *

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Facing the Truth
truthlies.jpg  

Charles Darwin hypothesized that emotions, especially those of the high stakes variety, involuntarily leak out all over our faces, even if we try to cover them up.  This provided the basis for a new study by Leanne ten Brinke from the Psychology Department at the University of British Columbia, Okanagan.  She studied the faces of 52 people making televised emotional pleas for the return of a loved one, in real missing persons cases.  Half of those people were later found to have been lying and were actually involved in the disappearance, some of which were murders.  By studying frame-by-frame video of five specific facial muscles that denote different emotions, those being deceptive were distinguished from those being truthful, with over 90% accuracy.  It is possible that this type of research could help police in future missing persons investigations.
          
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Revealing Raindrops

raindrops.jpgFossil raindrops, courtesy Nature
Fossil impressions of raindrops that fell in South Africa 2.7 billion years ago have been studied to predict what the earth's atmosphere may have been like then.  The impressions were formed and then preserved in volcanic ash.  And these fossilized impressions provide a huge clue for scientists like Dr. Sanjoy Som, an astrobiologist from The University of Washington in Seattle.  Because the sun was fainter 2.7 billion years ago, Earth should have been frozen, but it wasn't. So either the atmosphere was much denser, or greenhouse gases were much greater back then. An analysis of the raindrop impressions shows that the atmosphere was likely the same density as today - so something else was driving warmer temperatures - likely greenhouse gases.                

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Evolution Doping

runner_evolution.jpgCopyright Jos van Zetten
The "runner's high" is well known among endurance athletes, who report feelings of well-being, strength, and occasionally even euphoria during bouts of high intensity, long duration exercise.  Neuroscientists have confirmed that this is a result of a boost of drug-like chemicals in the brain - part of the reward circuitry that is also recruited when we eat desirable foods or have sex.  Dr. David Raichlen, an anthropologist from the University of Arizona, is exploring the evolutionary roots of the runner's high, which is thought to be associated with hunting behaviour.  The hypothesis is that it evolved to support early human hunting strategies of chasing prey animals into exhaustion.  Dr. Raichlen confirmed that another long distance hunter - the dog - experiences a similar activation of the reward system, while ferrets, who are not endurance hunters, do not.  

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Madagascar's Founding Mothers


Malagasy_woman.jpgMalagasy woman, copyright Steve Evans
The settling of Madagascar has been a mystery for hundreds of years.  The island is only 400km off the coast of Africa, but linguistically and culturally it has a strong connection to the peoples of Indonesia, more than 8000km away.  Dr. Murray Cox, a computational biologist at Massey University in New Zealand, was interested in investigating this mystery by examining the DNA of the Malagasy people.  He used hundreds of samples and computer algorithms to build up what is essentially a family tree, following the maternal line.  He has come to the conclusion that the first people on Madagascar arrived about 1200 years ago, and the founding population was a small group, including only about 30 women, likely from Borneo.  There seemed to be no further genetic input from Indonesia.  This suggests to Dr. Cox that a single ship, possibly lost or wrecked on Madagascar, was the source of these founding people.   

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Hyper-Planets

hypervelocity-star-625x450.jpgHypervelocity star leaving the galaxy, courtesy Center for Astrophysics.
Several years ago, astronomers discovered strange stars streaking out of our galaxy at tremendous speeds.  These stars turned out to have been part of binary star systems that had come too close to the super-massive black hole at the centre of our galaxy.  The tremendous gravity of the black hole had captured the binary pair, dragging one star closer, and "cracking the whip" on the other star, ejecting it on a trajectory out of the Galaxy at 2.5 million kilometers per hour.   Idan Ginsburg, a Ph.D candidate at Dartmouth College in New Hampshire, and his colleagues, have investigated what might happen if these binary stars had planets.  Their simulations found that planets could be ejected at even more incredible speeds of up to 30 million kilometers per hour, or nearly 5% of the speed of light.
   

Related Links
  • Paper to be published in Monthly Notices of the Royal Astronomical Society
  • Release from Dartmouth College
  • Release from Harvard Center for Astrophysics
  • National Geographic article
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Science Fact or Science Fiction: Robins and Worms

This is another episode of our occasional feature, Science Fact or Science Fiction. From time to time, we present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not. 

Here's today's statement:  "Robins can hear worms underground." To get to the truth, we went right to the source and contacted Dr. Robert Montgomerie from the Department of Biology at Queen's University in Kingston, who has actually studied this very subject.  He says it is science fact.

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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0


Saturday March 24, 2012

* Homo Mysterious * The Space Chronicles * Mercurial Mercury * It's a Bird, it's a Plane, it's ... Plankton??? * Fact or Fiction - Falling Penny *
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Homo Mysterious
red_deer_cave_man.jpg Artist's reconstruction of Red Deer Cave person.  Illustration courtesy Peter Schouten

There have been a lot of branches on the human family tree, including Neanderthals, Homo erectus, and many more.  Today, however, only one remains.  So, the discovery of what may be a new relative - and one that lived fairly recently - could have a significant impact on our understanding of human history and evolution.  Dr. Darren Curnoe, an anthropologist from the University of New South Wales, and his colleagues have reconstructed this human relative, based on fossils found in two caves in Southwestern China.  The creature they described is, in many ways, similar to modern humans, but with a more robust skull, a wider face, and large chewing muscles.  Dr. Curnoe suspects it may be a new human species, or a hybrid between modern humans and a more primitive form.
          
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The Space Chronicles

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Dr. Neil deGrasse Tyson is, perhaps, the best known astrophysicist in the world, and has become the face of space.  Dr. Tyson's day job is the director of the Hayden Planetarium, but he's also a frequent guest on TV talk shows, on PBS science programs, and will present a new version of the famous Cosmos program, originally hosted by Carl Sagan, in 2013.  Dr. Tyson is also a prolific writer, and in his latest book, Space Chronicles: Facing the Ultimate Frontier, he makes the case for a new age of space exploration.  He's convinced that doubling NASA's budget and reviving the dream of human space exploration will stimulate brilliant minds, drive innovation, and lead us to an ambitious new future.                

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Mercurial Mercury

mercury_colour.jpgImage: NASA/JHUAPL/CIW-DTM/GSFC/MIT/Brown Univ/; Rendering by James Dickson
Mercury, the samllest and most sunburned of the planets, has not really attracted all that much detailed study from planetary scientists.  For one thing, it's been hard to study.  Missions to Mercury have to cope with the same burning heat and radiation that scorch the surface of the planet.  But more than that, many scientists had assumed that Mercury was simply uninteresting - geologically dead for billions of years.  Well, now that we're getting a close look at Mercury with NASA's Messenger mission, that seems not to be the case.  Dr. Maria Zuber, a geophysicist at the Massachusetts Institute of Technology, and a co-investigator on the Messenger mission, and her colleagues reported this week at the Lunar and Planetary Conference in Texas, that Mercury shows signs of geological life, including massive uplifts of the surface that conventional geology can't easily explain.  

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It's a Bird, it's a Plane, it's ... Plankton???


The upper layer of ocean, just millimetres below the surface, is known as the neuston.  It is home to many different types of plankton, including bacteria, algae, and one of the most common, copepods.  Unlike their transparent relatives who live at greater depths, these 3mm long copepods are slightly larger and are blue or green in colour.  The colour protects them from harmful UV, but it also makes them visible to predator fish.  A new study by Canadian scientist Dr. Brad Gemmell, from the Marine Science Institution at the University of Texas in Austin, has found that these copepods have adapted an amazing survival strategy.    By moving their 5 pairs of appendages sequentially, they generate enough power and speed to break through the surface tension of the water and launch themselves into the air.  With a single jump, the copepod can travel 30 times its body length through the air, compared to an escape route of only 2 or 3 body lengths in the much more viscous water.  This enables the copepod to jump to the safety of an area clear of its predator's field of vision.   

Related Links
  • Paper in Proceedings of the Royal Society B
  • Not Exactly Rocket Science blog
  • Science Now story
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Science Fact or Science Fiction: Falling Penny

This is another episode of our occasional feature, Science Fact or Science Fiction. From time to time, we present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not. 

Today's statement:  When a penny is dropped from a tall building, it can kill a pedestrian below.  To get to the truth, we contacted Dr. Peter Sutherland, a Professor in the Department of Physics and Astronomy at McMaster University in Hamilton. He says it is science fiction.

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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0


Saturday March 17, 2012

* Diminutive Dinosaurs * Astronaut Eyes * Bees' Bugs * Here's Looking at you, Squid * Typhoid Froggy * Fact or Fiction - Brain Size *
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Diminutive Dinosaurs
mini_horned_dinos.jpg Unescoceratops koppelhusae (upper right) and Gryphoceratops morrisonii (lower left).  Courtesy: Julius T. Csotonyi

Two new species of horned dinosaur have been described and named, based on fossils found decades ago in southern Alberta.  Both are herbivores from the leptoceratopsidae family and lived during the late Cretaceous period.  Canadian scientist Dr. Michael Ryan, the Head and Curator of the Cleveland Museum of Natural History, was part of a team that identified both species by piecing together fragments of lower jaw bones.  The unique shape and size of the jaw bones provided the clue that these were different from each other and unlike anything else.  One, named Gryphoceratops, lived 83 million years ago and was less than one metre long, making it the smallest horned dinosaur ever found in North America.  The other, called Unescoceratops, is 75 million years old.  It was slightly larger, one to two metres in length.  The two new species are significant because they fill gaps in the evolutionary history of related horned dinosaurs like Triceratops, which came along later.
          
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Astronaut Eyes

bob_n_doug.jpgDr. Hamilton and Canadian astronaut Dr. Bob Thirsk.  Courtesy CSA
Space travel is risky.  Astronauts face the dangers of rocket launches, cosmic radiation and micro-meteoroids.  But they also face health risks from living in an environment humans aren't adapted to: zero-gravity.  We've known about the risks of muscle atrophy and bone decalcification associated with long-duration space flights.  Now, however, a new and perhaps even more serious concern has emerged.  Dr. Douglas Hamilton, now at the University of Calgary Medical School, worked with NASA as a physician and flight surgeon, and was flight surgeon for Canadian astronaut Robert Thirsk on his six-month tour on the International Space Station in 2009.  Dr. Hamilton and his colleagues have found that the microgravity environment of space flight increases intracranial pressure - the pressure of the fluid in the brain.  They've found that this affects the astronauts' eyes, reshaping the eyeball, putting pressure on the optic nerve, and even damaging the retina.  This changes and potentially permanently compromises the astronaut's vision, and this could have a serious impact on plans for extended duration space missions, like a trip to Mars.                

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Bees' Bugs


mattila.jpgDr. Mattila and a colony of friends.  Picture by Richard Howard
Dr. Heather Mattila is a honeybee ecologist at Wellesley College in Massachusetts, interested in what keeps a hive healthy and productive.  In her latest work, she and her colleagues have found that the key might be in their bugs.  Bees and their hives, like humans and other animals, rely on a complex community of micro-organisms.  These microbes help process the bees' food, and also resist pathogens that might invade the hive.  Dr. Mattila and her group found that the genetic diversity of the hive, which is determined by the promiscuity of the Queen bee, was an important factor in how diverse and healthy the colony's microbial community was.  More mates meant more microbes.   

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Here's Looking At You, Squid

giant squid eye.jpgLooking a squid in the eye.  Courtesy J Johnson, Smithsonian Institution
Colossal and giant squid are the largest invertebrates on earth.  Colossal squid, the larger of the two, can weigh up to 500 kilograms, with tentacles as long as 12 to 14 metres.  But they also have the largest eyes in the animal kingdom.  In both species, the eyes can measure 27cm in diametre, the pupils alone are 9cm across.  Scientists were mystified as to the purpose of such large eyes, because these squid live at depths where there isn't any sunlight.  But a new study by Dr. Dan Nilsson from the Department of Biology at Lund University in Sweden has discovered the reason.  Giant and colossal squid have maintained such large eyes for the sole purpose of spotting big objects at great distances - like sperm whales, their main predator.  As the sperm whale moves through the water, it disturbs many small gelatinous animals, which emit bioluminescence.  The big eyes of the squid pick up the subsequent glow around the whale at distances of up to 120 metres, enough space for evasive action.  

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Typhoid Froggy

pacific_frog.jpgPacific chorus frog courtesy kjfmartin
A fatal infection, called Chytrid fungus, has been devastating amphibian populations in many parts of the world, threatening hundreds of species with extinction.  One mystery about the fungus is how it spreads.  Dr. Vance Vredenburg, a biologist at San Francisco State University, and his student Natalie Reeder have found that the common Pacific chorus frog may be spreading it to other vulnerable amphibians.  Dr. Vredenburg was studying the impact of the fungus on the rare and vulnerable yellow legged frog, which was being devastated by the disease.  But he noticed chorus frogs living in the same habitat, and carrying huge amounts of the fungus, but somehow remaining largely unharmed by it.  He concluded that the chorus frog, which is common and travels widely, is likely spreading the infection up and down the west coast of North America.

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Science Fact or Science Fiction: Bigger Brains

From time to time, we present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not.  Today's belief is, "When your brain is bigger, you are smarter"

To help us with this 'matter,' we contacted Dr. Brian Christie, a neuroscientist in the Island Medical Program of the University of British Columbia, and a professor at the University of Victoria. He says it is mostly science fiction - although having certain areas of the brain bigger might make you smarter.

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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0