Category Archives: Evolution and Biology

Beyond Human Visibility

A couple of interesting scientific stories are making the rounds today, and worth a little physics and general science commentary. The first reminds us just how incredibly limited our sensory perceptions are in telling us about the world, by forcing us to imagine how it may look to animals whose perceptions are slightly different. The second reminds us just how little we know about our own planet. Continue reading

Dog Brains and Fishing Line: 2 Fun Articles

Nothing about quantum physics today, but … wait, everything is made using quantum physics…

Could you imagine getting a dog to sit absolutely still, while fully awake and listening to voices, for as much as 8 minutes? Researchers trained dogs to do it, then put them in an MRI [Magnetic Resonance Imaging] machine to obtain remarkable studies of how dogs’ brains react to human voices and other emotional forms of human expression. [MRI is all about magnetic fields, protons, spin, and resonance; particle physics!! more on that another time, perhaps.]   The authors claim this is the first study of its type to compare human brains to those of a non-primate species. Here’s something from the scientific article’s abstract:

We presented dogs and humans with the same set of vocal and non-vocal stimuli to search for functionally analogous voice-sensitive cortical regions. We demonstrate that voice areas exist in dogs and that they show a similar pattern to anterior temporal voice areas in humans. Our findings also reveal that sensitivity to vocal emotional valence cues engages similarly located non-primary auditory regions in dogs and humans… 

So it seems, as dog owners have long suspected, that we’re not just imagining that our best friends are aware of our moods; they really are similar to us in some important ways.

Here’s a BBC article: http://www.bbc.co.uk/news/science-environment-26276660

Once you’re done with that, would you like to build up your muscles?  No exercise needed, just call the University of Texas at Dallas.  They’ve found that “ordinary fishing line and sewing thread can be cheaply converted to powerful artificial muscles.  The new muscles can lift 100 times more weight and generate 100 times higher mechanical power than a human muscle of the same length and weight… The muscles are powered thermally by temperature changes, which can be produced electrically, by the absorption of light or by the chemical reaction of fuels.”  [Quantum Physics = cool!!] The quotation above is from an interesting press release from the university, reporting the research which was just published in the journal Science.  I recommend the press release because it mentions several interesting possible applications, including robotics technology  and clothing that adjusts to temperature.  Here’s also a nice article by Anna Kuchment (who’s on Twitter here):

http://www.utdallas.edu/news/2014/2/21-28701_Researchers-Create-Powerful-Muscles-From-Fishing-L_story-wide.html

Though evolution left us with many wonderful abilities, it does seem that, year by year, humans are becoming less and less practically useful.   But at least our dogs will comfort us in our obsolescence.

 

Happy (Chilly) New Year

Welcome 2014! And quite a start to the year, with a cold snap that rivals anything we’ve seen in two decades. I don’t remember cold like this since the horrid winter of 1994, when the Northeastern U.S. saw snowstorms and extreme cold that alternated back and forth for weeks. Of course, when I was a child in the 1970s, such chills happened a lot more often; I remember a number of New England mornings where I awoke to a thermometer reading of -20ºFahrenheit (-29ºCelsius) [244 Kelvin].

The scariest negative temperature numbers that one hears about from the media are associated with the “wind chill”, which is a number that is supposed to measure how cold the air “feels” to your skin.  But “wind chill” is a rather subjective and controversial measure — there’s no unique way to define it, since you’ll feel differently depending on how much exposed skin you have, on your body weight, on your age and conditioning, etc.  By contrast, the temperature measured by a thermometer is defined independent of how humans feel, and experts agree on what it is and means. Oh sure, people use different scales to measure it: Fahrenheit (F), Centigrade or Celsius (C), and Kelvin (K).  But the differences are no more than the distinction between meters and feet, or between kilograms and pounds; it’s straightforward, if a bit annoying, to convert from one to the other.

So everyone agrees the temperature is and feels extremely cold, But is it, from the point of nature, really that much colder than usual? To say it another way: it was 84ºF (29ºC) in southern Florida yesterday.  How much warmer is that than the -40ºF (-40ºC) that was registered in the cold Minnesota morning?

Well, you might first think: wow, it’s a difference of 124ºF (69ºC), which sounds like a huge difference.  But is it really so huge? Continue reading

Evolution [in]-Action

For general readership

Evolution really happens in nature: we know this from the frightening rate at which bacterial species, faced with our most powerful antibiotics, manage to find ways around them.

More precisely, a certain amount of natural variability and accidental mutations within bacterial populations, and the huge rate at which bacteria reproduce themselves (a single bacterium at dawn may be billions by sunset), essentially assures that eventually, simply by accident, and relatively soon, a bacterium will be “born” that is immune to any particular antibiotic. And then this bacterium, the sole survivor of the onslaught to which its siblings have succumbed, and reproducing by dividing into “children” that also can survive, soon gives rise to a subspecies of its own, against which this antibiotic is useless.  By using the antibiotic again and again, killing off the bacteria from other subspecies, we eventually assure that this unbeatable subspecies becomes more and more common compared to its cousins.

In recent years, bacteria have appeared for which no antibiotic treatment exists.  The rate of the evolution of these bacteria has outpaced the rate at which biologists and medical researchers can find and develop new antibiotic treatments.  The Center for Disease Control is extremely worried about this, and its director Tom Frieden just published a blog post that everyone should read.  Here’s one quotation:

To help draw attention to CRE and other top antibiotic-resistance threats, the Center for Disease Control recently published its first report on the current antibiotic resistance threat to the U.S. The report estimates that each year in the United States, at least 2 million people become infected with bacteria resistant to antibiotics, and at least 23,000 people die as a result.

Note this extraordinary statement: every year, 1 in 150 people in the United States will be infected with bacteria that are resistant to a classic antibiotic every year, and 1% of them will die, some fraction of them because of this resistance.  Let’s put that in perspective: assuming there were no increase in the number of bacteria or improvements in treatment over the next 50 years, your chance of being infected by such a bacterium during that time is roughly 25%.  In short, this will very likely happen to someone you know in the next few years, and someone in your family in coming decades.  (It’s already happened to someone in my extended family.)  And of course, since they are hard to fight, these bacteria are likely to spread, so the rate of infection will become worse if nothing is done.

Here’s another quotation: 

Every doctor must commit to use antibiotics only when needed, and to use antibiotics for only as long as they are needed. Patients need to understand that “more” drugs does not equal “better” drugs. The right treatment is the best treatment – and that isn’t antibiotics for every infection or every illness.

Now why is he making this point so strongly? Let me end by quoting from the preamble to the report he mentions:

The use of antibiotics is the single most important factor leading to antibiotic resistance around the world. Antibiotics are among the most commonly prescribed drugs used in human medicine. However, up to 50% of all the antibiotics prescribed for people are not needed or are not optimally effective as prescribed. Antibiotics are also commonly used in food animals to prevent, control, and treat disease, and to promote the growth of food-producing animals. The use of antibiotics for promoting growth is not necessary,
and the practice should be phased out.

I hope everyone pays close attention to Frieden’s post and its message, and spreads the word among the people that they know.  Doing so may someday help save the life of someone you care about, or even your own.