November 24, 2012 - In a Flap about Flight * Fish Swims With The Current * Wax-work Micro-Muscles * Using DNA to Save the World * Question of the Week: Herbivores


One of the staples of science fiction is the idea of creating life in the lab. They tend to be horror stories - from Frankenstein to Grey Goo.  But in real life, researchers are looking at ways to create new organisms from scratch with the power to change our world for the better in a new effort that's been dubbed Synthetic Biology.  Plus, we'll find out how to tune an electric fish; we'll hear about artificial muscles which are 100 times stronger than our own, and  and we'll learn how herbivores know which plants to eat. But first - Flying Fossils


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In a Flap about Flight
Archaeopteryx_lithographica.jpgReconstruction of Archaeopteryx, an early bird, from the Oxford Museum of Natural History.  Courtesy Ballista

For modern birds, the ability to fly evolved 130 million years ago.  But to get to that point, there was a progression that involved an ability to glide rather than actually fly.  A new study by Dr. Anthony Russell, a Professor of Zoology from the University of Calgary, looked at fossils of both the archaic bird Archaeopteryx and an early feathered dinosaur, Anchiornis, both from the Jurassic period 150 to 160 million years ago.   Both fossils reveal evidence of long, slender feathers, too weak to sustain fight and unsuitably arranged to generate lift.  Scientists conclude that both Archaeopteryx and Anchiornis could glide from perch to perch in the forest canopy, but would have found getting off the ground, as modern birds do, impossible.  This study supports the theory that flight originated from the treetops down, rather than from the ground up.
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Fish Swims With The Current

glass_knifefish.jpgA glass knifefish swimming in its own electric field.  Credit: S. Stamper and E. Roth
The glass knifefish is found mostly in rivers in Central and South America, and it emits an oscillating weak electric field.  It uses this to navigate and detect its surroundings.  When two or more fish come together, they must alter the frequencies of their fields in order to prevent jamming.  A new study by Dr. Sarah Stamper, a Post-doctoral Associate at Virginia Tech, has found that the combined frequency of the group, known as the social envelope, emits a characteristic low frequency all its own.  When a new fish joins the group, it raises the frequency of the social envelope in order to improve the perceptive quality of the electrical field.

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Wax-work Micro-Muscles

nano_yarn.jpgWax-impregnated Nanotube Yarn, courtesy Science.
A team of researchers, including Dr. John Madden from the Department of Electrical and Computer Engineering at the University of British Columbia, has invented a carbon nanotube "muscle" powered by the unique properties of wax.  Millions of carbon nanotubes are wound into a yarn-like fibre, which is then impregnated with wax.  Wax has the property of expanding by up to 30% when heated and melted.  When a current flows through the nanotube fibres, it heats the wax, causing it to expand, and pushes the nanotube fibres apart. This causes the yarn as a whole to contract, pulling with a force 100 times that of the same amount of human muscle.    

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Using DNA to Save the World


In the past dozen years, scientists have gone way beyond sequencing DNA to actually creating synthetic DNA in  the lab. The next step is to insert that DNA into a cell and create synthetic life. And some researchers think this will be the first step to creating novel organisms that could grow food, eliminate pollution and control climate change. How about a microbe that eats carbon dioxide and pees out pure diesel fuel? This promising and emerging field is called Synthetic Biology, and Toronto-based freelance journalist Alanna Mitchell came by to explain it to us.

Andrew Hessel is a Canadian researcher who calls himself a "genomic futurist" and works on synthetic biology with a company called Autodesk. He says that DNA is just code, and you can use it to program life. He sees a future where we can take a few cells from an individual, grow them up, and then use them to print a new replacement organ in a 3D printer. Or create unique viruses that only infect a specific cancer cell.

Dr. Mike Ellison is a professor of biochemistry at the University of Alberta, where he is bringing the engineering back into genetic engineering. He says we should think about individual components of a cell like we think about electronic components, and try to build "plug and play" organisms.

Dr. George Church is a professor of genetics at Harvard Medical School,and one of the visionaries in the field of synthetic biology. He sees a future where we change the DNA in a simple organism. like cyanobacteria, so that it takes in carbon dioxide, and excretes something useful, like fuel or plastic. He thinks synthetic biology has the potential to solve many of the world's problems, from pollution to climate change to poverty and hunger.

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Question of the Week: Herbivores

This is our occasional feature, the Quirks & Quarks Question of the Week.  You think of a question, and we'll ask a Canadian scientist to tell us the answer.  And today's question comes from Bryan Herdman in Corbeil, Ontario.  After watching a deer eat all of the flower buds of a hibiscus plant earlier this year, he sent the following email: "Since Hibiscus are tropical plants, it's logical to assume that a Northern Ontario deer had never encountered one before, yet it chose that one plant out of a small flowerbed.  How does a herbivore decide which plants are edible?"

To help us answer this question, we've contacted Dr. John Fryxell from the Department of Integrative Biology at the University of Guelph.

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