Physical modeling is used in all of the sciences to improve our intuition of important processes and for developing quantitative understanding. In this seminar, we will use the "Mark and Recapture" technique to explore how the size of animal populations can be estimated indirectly, using both physical models (beads in bags and cars in parking lots) and insect populations. We will meet for 2 hours at a time, once a week, for the first 5 weeks of the quarter. Attendance is mandatory and roll will be taken. Students will be required to find and present one example of a "Mark and Recapture" study during the last three meetings of the seminar. Grading will be on attendance and presentation.