Stickleback Evolution

The goal of this laboratory activity is for students to analyze sample specimens from populations of stickleback fish looking at specific characteristics such as spine length and armor plating to interpret the conditions driving evolution. Students will develop a hypothesis for the adaptation of local stickleback populations based on readings/video on the classic cases (such as those in Pacific Northwest populations) as well as knowledge of local environmental conditions in the intermittent estuaries of California. Specimen fish will be collected from a local estuary and students will measure the fish and their spines. They will count armor plates using a dissecting microscope. Students will use graphs and basic statistics to compare populations to determine whether they are locally adapted to be low armored, partially armored, or fully armored. Finally, student groups work to design a field study that could be used to test their revised hypotheses.