Chapter 52, Problem 11TYU

SCIENTIFIC INQUIRY Jens Clausen and colleagues, at the Carnegie Institution of Washington, studied how the size of yarrow plants (Achillea lmmlosa) 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 in the diagram.

Data from J. Clausen et al., Experimental studies on the nature of species III. Environmental responses of climatic races of Achillea, Carnegie Institution of Washington Publication No 581 (1948)

Clausen and colleagues proposed two hypo theses 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, how would you test these hypotheses?