Month: August 2010

Synthesizing the history of life

Sparking curiosity with the Toilet Paper Timeline, then following up with the beautifully drawn Cartoon History of the Universe seemed to work pretty well to keep students interested and engaged in their work. However, in putting it all together in their presentations we needed a simple graphic organizer to point out the highlights.

The History of Life on Earth timeline I put together to start with gives the broad overview, but we need to telescope the Cambrian to observe the really interesting, broad patterns in the evolution of multicellular life.

There are two key ideas I want students to get from these exercises. The first is what the Montessori lessons call the Gifts of the Phylum, which boils down to the fact that different Phyla represent major milestones in evolutionary development. For example, Cnidaria, the phylum of jellyfish, are important evolutionarily because they mark the emergence of organisms with endoderms and exoderms.

The second important concept regards the cycles of extinction and diversification that can be found in the fossil record. Dinosaurs emerge after the Permian-Triassic extinction event and diversify; large and small species, carnivorous and herbivorous, land based and ocean based. Similarly, after the Cretaceous-Tertiary extinction wipes out the dinosaurs, mammals take over and diversify to fill all the empty niches; elephants and mice, tigers and gazelles, rinos and whales.

Resurrecting the greenhouse

Two years ago, the middle school’s flagship project was to put up a fully functional greenhouse (using this design). It took all year but we did it. On the way, we got to practice geometry, mapping and construction, while learning and growing plants and studying soil profiles. It was so successful that, with our spring plant sale we broke even on the entire project.

Last year, however, the greenhouse was somewhat neglected. My plans to add an automatic window opener, which would have been a wonderful tie-in to our electronics and Newtonian physics studies, did not work out; we just did not have the time. We’d taken the plastic covering off, so only the bare, forlorn PVC frame was left standing around a plot of waist-high weeds.

Though I could not have predicted it, this year we have a strong core group of students who are highly enthusiastic about resurrecting the greenhouse and making it work. My suggestion was that we try to grow produce this fall that we could cook in December when we do our Dinner and a Show. Well, two weeks in, they’ve already put together a menu plan, weeding is well on its way and I’m being harassed to hurry up and arrange a trip to Home Depot. The excitement is so infectious that another student has volunteered to bring in his electric weed-whacker during the immersion. It’s amazing!

I’m having the hardest time not butting in. There is a beauty in seeing a well oiled machine executing a project or solving a difficult problem. But there is another even more wonderful aesthetic visible in a the birthing struggles of a nascent team. The forward motion of infectious enthusiasm is pulling puzzle pieces into its wake, and the pieces just seem to click into place when the time is right. I have to keep reminding myself that my job is to prepare the environment and let the kids do the rest.

Shades of grey

We’re focusing on the biological sciences in the natural world this year. I’m a great admirer of the sketches and illustrations in the notebooks of the great naturalists so that’s how I plan to integrate art. Our art teacher is a great help, and she started us up with sketching in pencil and our first exercise was to get a feel for the different soft pencils. The little panel we shaded in with B, 2B, 4B and 6B pencils is a nice metaphor for what we’re working on in middle school.

There was a bit of giggling though. Last year one of the poems presented was:

Said Hamlet to Ophelia,
I’ll draw a sketch of thee,
What kind of pencil shall I use?
2B or not 2B?
– Spike Milligan

This was just before we saw Hamlet in St. Louis. Though I don’t know if the poem make the famous line more comprehensible.

Hamlet in the park in St. Louis.

Finite resources

When will we run out of natural resources, either from depletion of non-renewables or overuse of renewables? Scientific American has a great interactive graph charting How Much Is Left that would tie in really well to our cycle on natural resources.

How Much Is Left? interactive graph. from Scientific American

The caveat is that it is notoriously difficult to really figure out how much of a resource is left. For one thing, there might be undiscovered deposits, or we could find ways of using it more efficiently to extend its lifetime. As resources get more scarce their price goes up which gets people more interested in discovering more or coming up with better, more efficient, methods of extracting things like minerals from alternative sources. If we start to run out of Lithium for batteries maybe someone will develop a process to extract it from seawater. Or, as oil gets harder to extract and its price goes up, perhaps there will be more investment in alternative energy technologies like wind farms, tidal generators and solar convection towers.

Music in the morning

We did poetry in the mornings last year at the end of our community meetings as a substitute for musical appreciation. However, the inestimable Anna Clarke, sent me the link to NPR’s 100 most important American musical works of the 20th century. The 8-13 minute long pieces include excerpts of the music, an interview with someone connected to the music and commentary by the NPR reporter. First on the list is ‘Adagio for Strings’ by Samuel Barber.

I’ve also caught their series on 50 great voices which is a great place to discover some truly iconic voices from around the world that I did not even know about.

Toilet Paper Timeline in practice

Who thinks they're at the most important event?

The Toilet Paper Timeline of Earth History worked as well as I’d hoped. The beginning was a bit boring, it was a challenge keeping the kids focused, since nothing much happens for a very long time. It helped that we had to unroll the toilet paper back and forth across the room, so I had a different student take over every time we had to turn around.

That was not quite enough though to keep them from getting distracted, however, so I also assigned people to stand at the location of major events. This worked out nicely in the end because it let me ask them, at the end, whose event was the most important? Most of them made some argument without any prompting; the group is already pretty comfortable with each other and are not afraid of speaking up.

During the unrolling, most events occur in the final two turns. Students did notice this fact, which is the ultimate point of the exercise. Getting them to talk about different events, like the time of the first multicellular organisms or the extinction of the dinosaurs, helped students own the work. All together, it seemed to strike their imaginations.

They also seem to like using Cartoon History of the Universe as their reading assignment.

The Pre-Cambrian. Nothing much happens for a long, long time.