Revolution#123, March 16, 2008


A Raucous High School Darwin Day: “Where’s the Proof?”

I had the opportunity to celebrate Darwin Day by doing a presentation on evolution to an assembly of about 70 students, mostly Black and Latino, at a proletarian high school. Most of the students at this alternative school have had trouble at other schools, and this may be their last chance to get any kind of education at all.

I tried to capture some of the awe and wonder that Darwin himself appreciated in the natural world and in the process of evolution, and of which these students were most likely deprived. The PowerPoint presentation consisted of photographs and illustrations drawing mainly from ideas based on the photo section of Ardea Skybreak’s book The Science of Evolution and the Myth of Creationism, Knowing What’s Real and Why It Matters. Questions from the students started to fly almost right from the beginning. This was not an orderly affair. It was raucous and rather contentious at times. And it was a lot of fun!

It’s impossible to capture fully the whole scene as it erupted, but I thought I’d share just a little of the flavor of what went on.

“How many of you have gone to the doctor and got antibiotics? And why does the doctor tell you to take all of them even if you start to feel better?” “So they can make more money,” one student replied. Everyone should know why finishing their antibiotics is important, so I explained how bacteria can become resistant to antibiotics. If you don’t take all of them, and some of the bacteria survive, these bacteria then become resistant to (unaffected by) that antibiotic. This is a big problem because those bacteria pass along to their descendants the ability to survive antibiotic treatment, thus producing whole strains of super bacteria. This is just a small example of evolution in action today. The science of evolution is not only something that is necessary to understand and explore the past, but is foundational for much of modern science, including medicine.

Things got really lively when I brought out how evolution was “descent with modification” and that all life on the planet started with a common ancestor and diversified through entirely natural processes with no need for a guiding hand of an unseen creator. One of the young men asked if I believed in god. When I replied that there wasn’t a god, he just shook his head. He explained that on a recent school field trip he had heard a talk by Dr. Johanson (the renowned paleontologist who discovered the fossil “Lucy”) and Johanson didn’t believe in god; then he went to his church school and “they say it’s god not science, and now you say there’s no god... I don’t know what to think!” putting his head in his hands. A couple of comments among the students were along the lines of “you’re going to hell,” or “he didn’t say that!” I went on to explain that humans invented religion as a way to explain things that they didn’t understand and that the Bible and the Koran ask that you accept things on faith, whereas science examines the real material world and is based on evidence.

Well, this led to a young woman asking a string of questions: “You say it’s not the Bible but evidence, where’s the evidence?” “Are scientists 100% sure of the Big Bang or global warming?”

One slide showed examples of the great diversity of life and a quote from Skybreak’s book—“How can we explain the great diversity of life on this planet? How can we know where humans came from? The answer lies in the science of evolution.” I asked the group to look at the photographs and say which kinds of life were related. “The whale and the star fish”... “The human and the ape”... “None of them”... “They’re all related!”

“Meet your ancestor!” I said, as a photo of fossil micro-bacteria from 3.5 billion years ago appeared on the wall. “What is that?” “We came from that?!” “Where’s the proof?” One way we know that all life came from a common ancestor is that all life on earth is made up of the same basic genetic raw material and no living thing uses any other kind of genetic material and process of replication. I described the environment at the time of the first micro-bacteria and how life on the planet has constantly changed and continues to change. And as part of that process of change there have been periods of mass extinction that paved the way for a greater flourishing of life.

Of course, the evolution of life is not pre-determined and some pretty amazing things have happened along the way. For instance, land life came from the sea (fish to amphibians) and continued to evolve, and then one form of land life (the whales’ ancestors) went from land back into the sea.

The students really were intrigued with the photos of the Tiktaalik fossil and an artist’s representation of what it might have looked like. (Tiktaalik is the first “transitional” fossil discovered of a creature that came from the water onto land some 375 million years ago.) “If it (Tiktaalik) came out of the water, how did it breathe? Fish breathe in the water, but they can’t breathe on land; and things on land can’t breathe in the water... are there fish with lungs?” “What caused Tiktaalik to leave the water?” I recounted the description by Neil Shubin (co-discoverer of Tiktaalik and author of Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body) of how the Tiktaalik fossils were found in what was an ancient sea where the fish were 16 feet long: “And you know how the saying goes—‘the big fish eat the little fish’...well that’s the way it was. So what kind of evolution would allow this species to survive? Grow bigger, get some kind of armor or shell, or get the hell out of the water!” Everyone was laughing at that, including the teachers.

One series of photos illustrated how evolutionary adaptation accounts for a large part of the diversity of life on the planet. The first picture was of a wolf chasing a snow hare (“That rabbit’s running for its life!”). What advantage does its white color give the hare (“To hide in the snow.”), and what would happen if it had a dark colored or a mixed color (“It would be eaten!”)? I spoke about how white hares might have evolved from hares of different colors as well as white, and the predator/prey relation as one of the things that drives adaptation. Many of the students were really drawn to photos of a walking stick and a leaf mantis, commenting on how much these insects looked like sticks or like leaves. It was pretty clear that they had never seen such things.

Next up was a photo of an embryo, which was large enough to fill the whole slide, and it drew quite a bit of attention. After describing that an embryo is the earliest stage of development of an organism, and pointing out the gill slits and tail, I asked what living thing is this the embryo of? “A cat.” “No, it’s not a cat.” “It’s a lizard...I’m sure it’s a lizard.” Eventually someone said, “it’s a human!” (But I think he thought it was a trick question.) I then explained what the gill slits and tail developed into in humans, and put up pictures of embryos of other animals, showing how similar the embryos are to each other at that stage of development. Evolution explains why this is so—because all living things come from a common ancestor.

What about humans? Where did we come from? I used an illustration of a branching “tree of life” for the primate line, showing how monkeys, lemurs, apes, and humans, etc., had a common ancestor, and in particular how closely related humans and chimpanzees are (photos of chimp/human skeletons; chimps using sticks for tools). One of the questions that was posed was that if humans evolved from apes, why are there still apes?

Finally we talked about what made humans uniquely human. As Ardea Skybreak writes, “We think, wonder, converse with each other—including about the distant past and the far horizons of the future.” We got into how biologically speaking there are no races—we are one species across the planet. And that all we humans have is each other, and that we matter to each other—and that with a scientific understanding of the world, it’s up to us to make the world a better place.

At the end, the young woman who was demanding proof for everything returned to the question of global warming and whether it was true or not. Is it possible for humans to go extinct and how would that happen? And if humans blew each other up or were wiped out by bacteria, and if all that was left was bacteria, would life evolve the same way where there would be new humans?

One of the teachers was challenged by the presentation. He confided that he believes in a creator, however it was good to open up the dialogue we can have. One of the questions he has is how did life come out of nothing? Another teacher was excited that the seeds about evolution had been planted among the students so that they know that there’s a scientific explanation for life, in contrast to the creationism which they’re heavily influenced by.

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