* Tagish Lake Meteorite * Flakes in Lakes * Mummified Beetles and Stingless Bees * Do You See What I See? * Jellyfish Junk Food * Clam Clones Sample other Species *

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Tagish Lake Meteorite

tagish_lake_meteorite.jpg Meteorite fragment, Credit: Michael Holly, Creative Services, University of Alberta.
Carbonaceous chondrites are a class of meteorites comprised of the same organic materials that were present 4.6 billion years ago when the Solar System was formed.  In January, 2000, a carbonaceous chondrite meteorite landed on the frozen surface of Tagish Lake in northern British Columbia.  Fortunately for scientists, its numerous fragments  were recovered in an uncontaminated state.  This allowed scientists, including Dr. Christopher Herd, a planetary geologist from the University of Alberta in Edmonton, to identify its components with greater certainty.  But in a new study of the Tagish Lake meteorite, four fragments studied closely were found to contain varying but high degrees of organic materials, notably amino acids - organic building blocks essential for life.  This further suggests these materials could have been responsible for life evolving on Earth.  It also indicates that the meteorite's organic materials were altered by a hydrothermal process when still part of the parent asteroid.     

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Flakes in Lakes

rice_coring.jpgTaking core samples from Rice Lake, Ontario.  Dr. Lisa Sonnenburg
Underwater archaeology has borrowed a technique from the world of geology to improve its capacity to search for microscopic fragments in murky depths.  Dr. Lisa Sonnenburg, from the School of Geography and Earth Sciences at McMaster University in Hamilton, used drill cores, similar to ones taken by geologists, to extract 'micro-debitage' from several metres of sediment at the bottom of Rice Lake in Ontario.  Micro-debitage is markings or evidence of human activity on microscopic fragments; in this case, flakes of quartz resulting from the making of primitive stone tools.  More than 150 flakes found in core samples provide evidence of paleo-Indian activity in the area 9,000 years ago.  The tools, made by some of Canada's earliest inhabitants, were possibly used for exploiting resources in was once a large marshland.    

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Mummified Beetles and Stingless Bees

Mummifying-bees.jpg An Australian stingless bee mummifies a small hive beetle.  M. Greco
When the small hive beetle enters the domain of the Australian stingless bee to steal food, it encounters a defense mechanism it has not seen before.  The small hive beetle is not native to Australia; in fact, it only arrived in 2000, possibly on produce imported from Africa for the Sydney Olympics.  The beetle is better equipped to face honey bees in their hive.  It does so by lowering its body under its hard shell, much like a turtle.  By doing this, the beetle avoids getting stung.  But new research by Dr. Mark Greco, an entomologist from the University of Bath in England, has found the Australian stingless bee has a different plan to combat the invading beetle.  It quickly prepares a cocktail of resin, which it extracts from trees for hive building and repair, along with a wax-like substance that it excretes, and mud. The mixture is called batumen.  When the beetle employs the 'turtle' defense, the stingless bee coats it with batumen, gluing it to the spot and mummifying the unsuspecting beetle alive.      

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Do You See What I See?

blue_eye.jpg copyright Laitr Keiows
In work earlier in her career, Dr. Charlotte Codina, from the Academic Unit of Ophthalmology and Orthoptics at the University of Sheffield, demonstrated that deaf people can see better than those with hearing.  In particular, she found that their peripheral vision seems to be more sensitive and discriminating.  This seems to be partly because deaf people have recruited part of the auditory cortex in the brain to work processing visual information.  However, this is not the whole story.  In her latest work, Dr. Codina has shown that neural changes occur in the eyes of deaf people as well.  Neural connections shift from the centre of the eye to the peripheral cells, suggesting that the deaf do actually see the world differently than those with hearing.

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Jellyfish Junk Food

Jellyfish can be quite beautiful, but they're mysterious creatures. And it turns out that, at least ecologically speaking, they don't play well with others.  Dr. Robert Condon, a marine scientist at the Dauphin Island Sea Lab in Alabama, has just done a study trying to understand the impact of jellyfish blooms on the marine food web.  Normally, marine food webs are efficient recyclers of the energy-rich carbon that photosynthesizing phytoplankton make, and many species can benefit from it.  However, jellyfish turn out to be a dead end for carbon.  The carbon these voracious eaters excrete isn't recycled and is lost to the marine food web.   

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Clam Clones Sample other Species

clam_clones.jpgCorbicula fluminalis, copyright Aad van Meerkerk
Sex has its advantages, but disadvantages as well.  Some clams have found a way to have the best of both worlds, though.  These hermaphroditic shellfish normally just produce clones of themselves.  Sperm enters the egg and kicks out the DNA from the egg.  So the baby clam is a clone of its father.  The clams often fertilize their own eggs, but can also steal those of other clams, even other clam species, robbing them of the rich resources of the egg.  This means the clams have lots of clonal offspring, but are lacking in genetic diversity, which is the fuel for evolution and adaptation.  But Dr. Shannon Hedtke, a biologist at the University of Texas at Austin, has found that, every once in a while, the clams keep just a little bit of DNA from the eggs they steal, essentially meaning they have a little bit of sexual reproduction every now and then, to add a bit of genetic diversity to their clonal legacy.    

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