BIO 112 Lecture Notes - Lecture 1: Influenza Vaccine, Confounding, External Variable
Document Summary
Observed relationship could be due to coincidence, external variable that affects both a and b, a causes b/b causes a. Important to do more testing to see if there is causation. Proximate causes- genetic or biochemical basis for variation. Beak size is due to genes (bmp4 molecule) Ultimate causes- processes of mutation, natural selection, and evolution bring about differences. Beak size is due to differences in diet. Natural history and discovering patterns in nature. Hypothesis- educated guess about cause and effect. Make assumptions clear and unambiguous (if) and make specific predictions to test these assumptions (then) Functional mapping of outcomes (dependent variables) on conditions (independent variables) Testing different amounts of fertilizer (independent) on plots of land to see plant growth (dependent) Need a control for each plot of land tested. Control and fertilizer spots need to be interspersed to prevent confounding variable. Testing flu shot to see whether it prevents the flu. Current organisms give rise to new organisms.
