When an Explosion is not an Explosion

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Many of you have probably heard of the “Cambrian Explosion.”  This is the commonly used term to describe a time in the history of life when life moved from fairly simple multicellular life to a huge diversity of life.  It is seen as one of the defining moments of evolution since many different biological forms were experimented with and produced.  The period of history has been the subject of massive investigation for years.  However there is one really common misconception about this event that comes from the name itself.  Explosion makes people think of a quick event, this was not that.  The Cambrian “Explosion” was actually about eighty (80) million years long.  To put that in perspective, the event that ended reign of the dinosaurs (the so-called KT event) occurred only 65 million years ago.  Realistically it is more like the Cambrian Slow Burn.

Why is this important?  The Cambrian Explosion is a common target for people who want to say the Theory of Evolution doesn’t work.  The common argument goes something along the line that such wild diversity of life could not have independently evolved in a short time.  I’m sorry but eighty million years is hardly a short span, but it is easy to see how the term can be twisted.  This just highlights the fact that you should always look at all the facts involved in an argument .

What a rash can teach us

Rash

The picture at the top is a rash that developed on my hand the other day after being in the sun for five minutes.  I have since had some amount of the rash for going on three weeks and am seeing a dermatologist for it, but it made me think about the things a rash can teach us about biology and microbiology.  I was thinking about this because one of the hardest things I have to try and get across to students about science is that you have to go in with an open mind when trying to actually do science.

My dermatologist is currently trying to decide if the rash is the result of a benign condition called Polymorphous Light Eruption (PLE, a hyper-reaction to UV radiation common in people during early spring) or an autoimmune condition called Dermatomyositis (DM, an autoimmune condition where the body attacks it own skin and muscles).  Either way it results from my immune system responding to UV radiation in an inappropriate manner and requires some steroid treatments to fix.

I bring up this rash  because every year I ask my BIO220 students about how Dr. Sterne first discovered that Lyme disease was an infectious disease.  The answer is fairly simple, that the disease was treatable with penicillin, yet a majority of students miss it.  The majority of students opt for the distinctive rash of Lyme disease meaning it is infectious.  I know most students intuitively realize that a rash is not, by itself, an indicator of infection (think poison ivy, psoriasis, or eczema), but the students get tunnel vision and fill their heads with visions or measles or Lyme disease before they think through the question.

The take home message is that you need to spend a moment in my classes to think before you answer and learn to rely on that huge amount of intuitive information you have access to.

Dynamic PowerPoint Slides

Most people think of PowerPoint as something akin to the old trays of slides we had to make when I was in graduate school, static and about as interesting as your uncle’s vacation pictures from the World’s Largest Ball of String museum.  Recently things have started to spruce up with slide animations and transitions.  Some similar tools (notably Prezi) have taken this to a motion-sickness inducing extreme.  What people don’t realize is that the animation and transition tools available in PowerPoint (or any other modern presentation software, like Keynote) can also provide you with a way to deal with one of the biggest problems in educational presentation, how to make the slides useful inside and outside the presentation itself.

Anybody who studies the art of presentation for long realizes that “less is more” is true when trying to present to an audience.  If your slides are too cluttered or wordy people do not listen to the presentation but rather just try and read the slide (tuning your melodious voice out).  However, when someone (say students) is looking at the slides later they may not have access to all your pithy wisdom and spot-on observations (let us imagine they don’t take good notes).  In this situation, a minimalist slide approach can prove to be of very little use to the students… so how do we compromise.  My method is to utilize the tools that PowerPoint provides so I can embed further information in the slides.

Take the following slide

A typical presentation slide, minimal and focused on the key term or concept.
A typical presentation slide, minimal and focused on the key term or concept.

While this slide is good for my presentation style (minimal, focused on the specific concept), it may prove of little use to someone after the class.  However, with a simple trick, I can embed a large amount of data in the slide for later use.  Notice the icon in the lower right of the slide (see image below).

Arrow pointing to help icon embedded in file.
Arrow pointing to help icon embedded in file.

This little icon uses a simple iconography denoting aid or help and it also serves as a trigger for an animation that does not appear in the actual presentation unless you click on the icon.  Now look at how the slide changes when you click on this icon.

Slide with extra information.
Slide with extra information.

Triggering the animation reveals a more detailed explanation of the concept, something the students may have not gotten from their notes or that you may want to emphasize.  This is a fairly simple example that can be accomplished by simply animating an object with a specific trigger (the option is found in the ribbon as “trigger”), but the concept can be expanded to allow nonlinear progression through talks using hyperlinks (maybe adding a subset of slides to allow extra practice on a problem concept) or to add extra materials (hyperlinks to exterior material).  The possibilities are actually very broad, you just have to start thinking of PowerPoint as the dynamic tool it can be rather than placing it in the same mold as the old slide trays we used to lug around.

One note is that in order for students to use these tools they will need to run the actual presentations, not just look at the files.  The good news is that files like this can be viewed for free within Microsoft’s free PowerPoint online version, which is very easy if you share the files on a Skydrive account.

The Top Ten Things Students Should Know

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Every term I get a new crop of students and they always tell me they are going to get a 4.0 in my class.  I know this won’t happen (usually only around 10-20% will score that well) but I tell them to do their best and we will see how they do.  Around half-way through the term a number of them come to me and ask what they can do to improve their grade and I try to help them, but by then the habits that are failing them are set in.  So I thought I would take a moment to write down a few things I have observed.

  1. Come to class, no seriously, come.  If you skip class or worse, sleep through class, you can never hope to get an understanding of anything more than the most basic concepts.
  2. A class is only as active as the students want it to be.  I plan a number of interactive components into my lessons, but often they just fall flat because when I ask for your participation you just stare at me and wait for me to fill in the silence.  Ask questions, respond to queries, these are the ways to make learning more active and it helps to integrate the information in your head better.
  3. Do the reading.  If class is the first time you have seen the concepts we are going to discuss, you are already behind the curve.  Read all materials assigned so you can come prepared to ask questions about the materials that make no sense.
  4. Take notes, and then rewrite them.  I publish all my PowerPoint slides of my lectures, but again, learning is not a passive process.  You need to take notes over materials before class and then go over them during and after class to fill in the blanks and reorganize the materials for your own cognitive map.
  5. Your handwriting, spelling and grammar count.  I know this isn’t a writing class, but at the same time I can only assess what you actually wrote (and can interpret), not what you intended the scribble to mean.  Misplaced punctuation, careless spelling, poor penmanship can all lead to your answer saying something completely different than you intended.
  6. Deadlines are there for a reason.  Just like in a job, I have expectations of when your work should be done and I stick to them.  This is laid out at the beginning of the course and you will suffer consequences if you do not meet the deadlines.
  7. Come to me with solutions not excuses.  As I learned in business, the person who comes with a solution to a problem they are presenting is listened to more than someone who just comes with excuses for why the problem exists.
  8. Come to think of it, just come see me for starters.  If you avoid me after class and then ignore poor grades, I assume you don’t care about your grade.  If you need help, seek it out.  I may be intimidating, but it is time to put the big kid underoos on and learn to ask for help.  Your grade is your own, take responsibility for it and its outcome.
  9. If you make a mistake, own up to it.  If you do something you shouldn’t (we are talking academic dishonesty here), the consequences will be much worse if I have to call you out on it.  If you do something you shouldn’t, don’t make excuses and hide from it, accept that you did wrong and face the consequences.  Honest contrition can go a long way.
  10. In the end, realize your grade is your own and it is a summation of all your work.  The grade for a course is not decided on a single exam or project.  The grade for a course is the product of many, many assessments all summed together.  It is similar to when a basketball player is harassed for not making the last second shot, does he bear the whole burden of the team losing?  What about his teammate who shot two for twenty from the free-throw line or the other teammate that kept laying bricks from the three point line, don’t they share some of the blame for the lose?  Your grade is about your performance through out the term, if you do poorly at the beginning it will be hard to pull it up at the end.  Likewise, if you become lazy at the end, the grade can plummet.  No one gives you a grade, you earn it.