My advisor, Rowan Martindale, has been discussing climate change through geologic history in her earth history class for the last couple of weeks (including my favorite event, the Paleocene-Eocene Thermal Maximum) so in lab, we decided to have the students do an experiment to see what happens to calcium carbonate organisms in acidified water. I had recently collected some bivalve shells on a trip to the beach, so the students picked three types of shell: a mussel, which has a thin shell and acted as a control because it had both valves still attached, so one could be put in water and one in acid; a clam, which had a medium-thick shell; and an oyster, which had a very thick shell. I put the shells in glass beakers and poured in diluted hydrochloric acid, while the control valve of the mussel sat in water. The students hypothesized what would happen to each shell after one week. The class was very excited when the shells began to bubble and fizz in front of them. After a week in the fume-hood I rinsed the shells and let the students examine them. Nothing changed about the mussel in the water, however the mussel in HCl completely dissolved. In a fun twist, the periostracum, or the organic layer of the bivalve, was leftover, which looked gross but got the attention of the students. The other shells were clearly abraded, however the effect was not as dramatic as the mussel. It was a fun activity and we were able to discuss not only ocean acidification, but experimental design, hypothesis testing, as well as some of the flaws with our experiment and why the shells aren't a perfect analog for living molluscs. Below are some pictures of the experiment:
L,M: Carefully pouring acid into the beaker R: Our oyster fizzing in reaction to the acid
Check out my blog post on Science Y'all, the Jackson School of Geosciences official student blog, where I accept the Up Goer 5 Challenge:
www.jsg.utexas.edu/science-yall/challenge-accepted-survival-lessons-from-ancient-building-animals/
For more on what the "Up Goer 5 Challenge" is, check out this post by my colleague Rachel Bernard:
www.jsg.utexas.edu/science-yall/up-goer-five-challenge/
Photo Credit: US Fish and Wildlife
Recently, I was teaching my lab students about taphonomy and deposition when I was inspired to create a game that can be played in class to help students understand some of the fundamental principles of taphonomy. Taphonomy is the study of what happens after you die- in the most literal sense. Paleontologists and sedimentologists study the processes that impact an organism after it has died - from how it is killed to decay to fossilizing to being dug up - and how that results in the fossil record. Deposition plays a big role in this - fossils that are buried are better protected from things like scavengers and storms, which can destroy remains and decrease their chance of preservation. While many taphonomic processes occur in predictable ways, the timing may be stochastic, or apparently random. It was important to me that the game portray this and how rarely fossiliation occurs, and how taphonomy affects the final set of fossils we can find and study as paleontologists.
I teamed up with my PhD Advisor Rowan Martindale to make a card game that can be printed out from a computer and played in a classroom setting in 30-40 minutes. Rowan is working on a Lagerstatten site - a place that has exceptionally preserved fossils - where the preservation style is linked to environmental change in the Jurassic. The game will feature the fauna found at this site, like lobsters, clams and ammonites. This will be public outreach associated with an NSF grant Rowan received for this work. The final product will be freely and publicly available and able to be played without any extra materials other than paper and ink, which will hopefully make it accessible to everyone. We will also create a follow up work sheet that will be used to assess student learning outcomes. We plan to test the efficacy of this game in teaching students about taphonomy, and produce a geoscience education paper introducing it. We started hashing out the game this week, and we quickly put together a working (and fun!) prototype. Here we are, testing the game on out on nerds from all across the university (as you can see, we kept our test subjects well hydrated). Keep an eye out for the finished product! |