by James Morris
Over the summer, I read an article called “Teaching that Sticks” by Chip and Dan Heath. Why do some lessons stick and others don’t? The authors identify several characteristics that describe what they call “sticky teaching.” One of these is curiosity. If students are curious, they engage more and tend to remember what they learn years later.
The authors caution about jumping too quickly to the answer when teaching. We all want students to reach the “Aha!” moment, the Heaths explain. But they suggest that this only works if there is a “Huh?” moment that comes first, a time when students are confused, even puzzled. Out of this confusion, curiosity arises.
They refer to a behavioral economist named George Lowenstein, who writes that curiosity comes from what he calls “gaps” in what we know. According to Lowenstein, we feel these gaps when we watch sports and read mystery novels – in both cases, we are curious to see what happens, how it will end, or who did it.
So, I decided to apply this approach to my own teaching. I began a college-level class in evolution not with what we are covering or by going over what to expect, but instead by simply asking questions. No answers, just questions.
Why, for example, are organisms so different from one another, and, at the same time, so much the same? Think about it. Organisms differ in size, shape, color, behavior, where they get their energy from, how they move about (or if they can move about), how many legs they have (or whether they even have legs). But, they all share the same genetic material, the same amino acids, and the same proteins.
Why so different and so similar?
And, if natural selection is all about struggle and competition – Tennyson’s “Nature, red in tooth and claw” – why do we find innumerable instances of cooperation in nature? Insects pollinate flowers, each deriving a benefit. A lichen is a partnership between a fungus and alga (which have taken a “lichen” to each other).
Closer to home, in the human body, bacteria outnumber our own cells by a factor of perhaps 10 to 1. This team of bacteria – our microbiome – is not causing disease, not just along for the ride, but essential to our health.
Our very cells harbor the remnants of what were once free-living bacteria, but now are small organelles inside of our cells called mitochondria that harness energy. This is quite an intimate partnership.
Cooperation occurs not just between two species, but also among individuals within a single species. Bees live in colonies where most of the females, the workers, forego reproduction. Some squirrels and monkeys sound alarm calls to warn of approaching danger, putting themselves in harm’s way. Vampire bats regurgitate blood to nest-mates. And, of course, humans, though known for horrible acts of violence, are also known for tremendous acts of self-sacrifice.
If natural selection is all about competition, where does cooperation and altruism come from?
And then consider this question. Look around the world and you will find many wonderful adaptations, such as desert plants that resist drying out, or lions adapted for tracking, hunting, and capturing prey, or the human eye with all of its intricate parts enabling us to see the world around us. But look around again and you will notice just the opposite. Many traits are harmful, like cancer or cystic fibrosis or Lou Gehrig’s disease.
Why hasn’t natural selection rid us of diseases?
Then there are traits that, while not really beneficial or harmful, don’t really make any sense. Let’s look more closely at the eye (so to speak). The light sensitive tissue – the retina – is made up of three layers of cells: one that converts light energy into electrical energy, a second that passes the signal along, and a third that sends the signal to the brain.
You might expect that the light-sensitive layer would be up front, where the light comes in. That would make the most sense. What you would not expect is to have it at the back, far from the entering light. If that were the case, the light would have to pass through the other layers before reaching the light-sensitive layer. That would make little sense.
But that’s exactly the way it is: inside out. Why?
New species arise through the process of speciation, giving rise to the enormous diversity of species we see today. How, then, can we explain their disappearances?
Why do organisms go extinct?
And there are questions that we can take from the pages of the history of science. Most of us are familiar with the famous finches of the Galápagos Islands, now often referred to as Darwin’s finches. The finches are the very icon of evolution by natural selection. Each one has a beak adapted to the food it eats, whether it’s insects, or cactuses, or even – in the case of the Vampire Finch – blood!
If the finches are one of the best examples we have of evolution in action, we might expect them to figure prominently in Darwin’s famous work – On the Origin of Species. But there is no chapter or even section on the finches.
Why did Darwin leave out the finches?
And, finally, evolution is not just the stuff of museums or relegated to the pages of history – it’s an active field of research today and relevant to many of our most pressing problems. Evolution can help us understand the emergence (the evolution) of antibiotic-resistant bacteria, one of the most concerning public health problems of our day. It can help us in our efforts to conserve what’s left of the diversity of species on this planet. It is shedding light on our recent history and how human populations are related to one another.
But, poll after poll comes up with the same result: fewer than half of Americans “believe” in evolution.
If evolution is so widely relevant, why is it so widely rejected?
Why indeed. Perhaps you are a bit curious.
© James Morris and Science Whys, 2014