Chapter 40, Problem 7TYU

SCIENTIFIC INQUIRY Jens Clausen and colleagues, at the Carnegie Institution of Washington, studied how the size of yarrow plants (Achillea lanulosa) growing on the slopes of the Sierra Nevada varied with elevation. They found that plants from low elevations were generally taller than plants from high elevations, as shown below:

Clausen and colleagues proposed two hypotheses to explain this variation within a species: (1) There are genetic differences between populations of plants found at different elevations. (2) The species has developmental flexibility and can assume tall or short growth forms, depending on local abiotic factors. If you had seeds from yarrow plants found at low and high elevations, describe the experiments you would perform to test these hypotheses.