Pictures of Arabidopsis Domestication Project Life Sciences for a Global Community Kay Gamble

Plants in CO 2 Chamber Plants grown in chamber One of two trays that sprouted

Plants in CO 2 Chamber Tray with no sprouts (odd)CO 2 Chamber

Plants in the CO 2 Chamber The students planted 3 trays of seeds and placed them in the CO 2 Chamber for the duration of this generation. They had bigger, softer leaves and bolted much later than the plants under the plant lights. We lost one tray to neglect and one never sprouted.

Plants under grow lights Notice some seeds had not germinatedPlants vary in size

Plants under grow lights More views showing differences in plant size Front plants are crowded yet larger than others

Plants under grow lights First bolt of this generationPicture taken

Plants under the grow lights The only plant that has boltedClose up of wonder plant!

Still only one plant producing seed This photo and the one on the right are of the same plant This “wonder plant” kept producing seed

Birds-eye view of all the plants Circled plants were grown in the CO 2 Chamber – They were the last to bolt.

Evidence of Diversity The Arabidopsis project gave my students an opportunity to see diversity among individuals played out in the classroom. Their frustration with their plants not sprouting or bolting at the same time as the “Wonder Plant” lead to better understanding of environmental pressures helped along by questions from me.

Wonder Plant This plant bolted a full two weeks before any other plant and continued to make flowers and seed for several weeks much to the delight of its owners!

Reasoning The plants which grew well, especially the one which bolted first and pumped out thousands of seed, were well suited for the environment in the classroom. Would those same plants have done as well out in the meadows of Romania? What about the plant early to bolt? What would have happened if the weather had changed suddenly. Could it have survived and been the most successful in other environments?

The later sprouting and bolting plants may have been more successful in other circumstances. The CO 2 chamber plants grew differently than those under the grow lights in the classroom. They had softer bigger leaves. Why? While they grew bigger leaves they bolted later. In fact they were the last to bolt. We discussed humidity as a factor in leaf size and thickness.

Comparison of CO2 Chamber with Grow Lights in Room Softer, thinner, larger leaves of plants grown in CO2 Chamber Thinner but thicker leaves of plants grown under lights

CO 2 Chamber vs Grow Lights Plants grown in the CO 2 Chamber gave the students more opportunities to see the differences the environment can elicit from organisms. The best hypothesis was determined to be due to humidity not CO 2. Experimental design to test the hypothesis were discussed but not carried out.