Paleofantasy * Why Vermin Can't Vomit * Squirrel Stress Makes Big Babies * Better Bacterial Biofuels * Big Stars make Long Gamma-Ray Bursts

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How did our ancestors live and can we learn lessons from them on how we should live today?  Well, a guest on today's program says we don't know, and probably not, and warns us against putting too much faith in a Paleofantasy.  Plus, we'll learn why voles can't vomit and rats can't retch; we'll hear how mother squirrels give a boost to their babies when population booms; we'll learn how to create E.coli bacteria that can cook up some gas; and we'll hear about a gamma ray burst that burst into the record books.

 

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Paleofantasy

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Modern humans have been around for about 200,000 years - most of it in the Paleolithic period, or Stone Age.  But about 10,000 years ago, humans began planting crops and breeding animals, which led to a dramatic change in diet and lifestyle.  There are those who believe those changes in diet and lifestyle that came along with agriculture - and more recently with industry and technology - happened too fast for evolution to catch up.  They feel we are out of sync with our modern environment, and should live and eat more like our Paleolithic ancestors.  But Dr. Marlene Zuk, a Professor of Ecology, Evolution and Behaviour at the University of Minnesota is not one of them.  Her new book, Paleofantasy, What Evolution Really Tells Us About Sex, Diet and How We Live, argues that neither we, nor any other species, have ever been perfectly suited to their environment.  Just like our 'caveman' ancestors, we deal with change by continually evolving.

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Why Vermin Can't Vomit

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picture copyright Jans Canon.

The vomiting reflex is known in many mammals, including primates. But rodents, which comprise about 40 per-cent of all mammals, cannot.  New research by Dr. Charles Horn, an Associate Professor of Medicine and Anesthesiology at the University of Pittsburgh, has found that rodents, including rats, mice, voles, squirrels, guinea pigs and beavers, lack the physical capability and the neural circuits necessary to initiate the reflex.  Instead, rodents have evolved a more efficient response to taste that makes them better at avoiding toxins.  But when they do get sick, rodents also eat clay, which latches onto the toxins and prevents the body from absorbing them.  It is hoped that this research can provide a better understanding of human vomiting, related to chemotherapy, pregnancy, digestive disorders and post-operation problems. 

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Stressed Squirrels Make Bigger Babies

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Red Squirrel mother carrying pup, courtesy Ryan W. Taylor

The stress of overcrowding causes red squirrel mothers to make bigger babies, according to new research from the Kluane Red Squirrel  Project in Yukon.  Dr. Andrew McAdam, a professor of Integrative Biology at the University of Guelph, is one of the investigators on the project, and recently he and his colleagues investigated how population booms change how mother squirrels engineer the development of their young.  They installed playback devices around squirrel nests to play squirrel territorial calls, so as to convince mother squirrels that there were lots of other squirrels around.  The mothers' stress hormones increased, and this led to faster growing offspring whose size would better equip them for a highly competitive environment.

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Better Bacterial Biofuels

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Bacterial culture.  courtesy M. Littlejohn
Biofuels, such as biodeisel and ethanol, could have a big role in reducing our dependence on fossil fuels.  However, biofuel production is still, for the most part, complicated, labour intensive and often energy inefficient, and the biofuels themselves are often not well adapted to our engines and vehicles. But using the techniques of synthetic biology, Dr. John Love, an associate professor of Plant and Industrial Biotechnology in the Department of BioSciences at the University of Exeter, has produced a new kind of biofuel using a special strain of E. Coli bacteria.  He has introduced genes from other organisms into the bacteria so that it can, in one step, turn simple sugars into a form of biodiesel that is indistinguishable from petrochemical fuel.

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Big Stars make Long Gamma-Ray Bursts

Gamma Ray Bursts are intense and powerful bursts of radiation representing some of the most powerful phenomena in the universe, such as a supernova collapsing into a black hole.  Ordinarily, they last only seconds, but on Christmas day, 2010, a burst was observed that lasted half an hour, and since then, an even longer burst has been observed.  Dr. Andrew Levan, an astronomer at the University of Warwick, thinks he now knows the source of these anomalous long bursts.  He thinks they come from super-giant stars exploding and then collapsing, and the duration of the burst is related to just how long it takes these extremely large stars to collapse into a black hole.

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