Biochemical Soul Musings on Nature, Science, Evolution, Biology, and Education


Morphed and Meeting Evolutionary “Needs”

I'm jealous!

Christie over at Observations of a Nerd (one of my favorite science blogs), somehow got noticed by the National Geographic Channel and received her own early DVD copy of their upcoming Darwin Specials for review. I highly recommend everyone read her sneak-peek at the upcoming "Morphed" series, which explores the evolution from ancestor beasts to whales, birds, and bears (also check out Christie's coverage on the new whale findings).

I'm guessing that many other science bloggers received the same email that I did, but I at least recieved a message from NGC's Digital Consultant, Minjae Ormes, with a "Party Invitation" to join them for Morphed, Darwin's Secret Notebooks, and Monster Fish of the Congo. Considering that I am greatly anticipating my chance to watch Morphed this Sunday, I am more than happy to advertise the programs below.

It sounds like a wonderful program with advanced CGI bringing the course of evolution to visual life, and with a good amount of intriguing science to back it all up.

That being said, Christie brought up one criticism that hits home for me, having taught evolution to undergraduate non-scientists. To quote Christie,

"They kept saying one thing that just got under my skin - they phrased adaptations as "solving" evolutionary problems. Species need to swim better? It must evolve a more muscular tail and streamlined body?! As convenient as that would be, that's not how evolution works. It doesn't see a problem and tackle it head on. OK, so it might seem nit-picky, but hey, that's what I'm here for."

Actually, I don't think this is nit-picky at all. In fact, I view it as a cardinal sin in teaching evolution. It gets right down to the fundamental mechanism of evolution: namely that there is NO "intended" direction in natural selection - no plan - no design - no dependence on needs.  It's very very simple - those individuals that happen to be better at doing some particular thing - a thing that makes them better eaters, better survivors, better reproducers - are more likely to pass on their traits. Thus over time, the population changes.  That's it, really.

However, I'm torn over how much to fault the NGC for using this type of literary or metaphorical storytelling device. Its human nature to see effects caused by needs. And based on my own experience in the classroom, it seems to be one of the most difficult evolutionary concepts for students to learn, which I have found a little surprising.

Here's an example: In a class on Topics in General Biology for freshman non-majors, I have given quiz questions such as these two (setup with a chart showing various characteristics of different lizard species):

According to the theory of natural selection, where did the variations in body size in the three species of lizards come from?

  1. The lizards needed to change in order to survive, so beneficial new traits developed.
  2. The lizards wanted to become different in size, so beneficial new traits gradually appeared in the population.
  3. The island environment caused genetic changes in the lizards.
  4. Random genetic changes and sexual recombination both created new variations that “worked better.”

What could cause one species of lizard to change into three species of lizards over time?

  1. Groups of lizards encountered different island environments so the lizards needed to become new species with different traits in order to survive.
  2. Groups of lizards must have been geographically isolated from other groups and random genetic changes must have accumulated in these lizard populations over time.
  3. There may be minor variations, but the lizards are essentially alike and all are members of a single species.
  4. In order to survive, different groups of lizards needed to adapt to the different islands, and so all organisms in each group gradually evolved to become a new lizard species.

A disarmingly large number of students answered 1. or 2. and 1. or 4., respectively (the correct answers are 4. and 2.). Okay, no big deal as it was a quiz based on the reading - perhaps they didn't read carefully enough (or at all).  So I used the quiz results to launch into a lecture on exactly why "needs" are completely irrelevant in evolution, hitting the concept quite hard.  We talked about specific examples in the animal kingdom, and it seemed like everyone understood the randomness of the underlying variability and the non-random yet unplanned outcome of natural selection.

But what happened when I gave them almost exact replicas of the question on the next exam? A good number of the students still gave answers indicating adaptation based on environmental needs!

Was this due to a lack of studying? A lack of interest in the subject? A failure on my part to make the concept reach their deeper cognition? Or was it due to some inherent difficulty in seeing things that look designed as arising without intended direction?

I must note that most of my better performing students found the question extraordinarily easy and I saw much eye rolling as we went through the exam afterward. So is there some fundamental dichotomy in the ability to understand this concept - can some people just not "get it" without immense effort?

I don't know the answer to this.  I think it may be just as likely that the students who didn't get it had just been partying too much or studying not enough.

So to what degree do we chastise the NGC for using misleading language to describe evolution as "solving problems"?  I'm not sure.

Nevertheless, I want to make it absolutely clear that "Morphed" sounds like an otherwise amazing program and I am incredibly excited to watch it this Sunday. As an aside, I highly recommend the PBS "evolution" series, particularly "Great Transformations" which also covers whale evolution beautifully.

Now I give you the National Geographic Channel advertisement:

Darwin Specials

Darwin Specials