Dr. Theresa Pagano, a biologist, has found that the checkerspot butterfly is becoming more prevalent in regions farther north than before and less prevalent in regions farther south. The northward shift of the butterflies is almost perfectly correlated with the northward shift of the warm zones in the global climate, and Dr. Pagano has ttherefore concluded that the changing climate is responsible for the northward movement of the butterflies. Each of the following, if true, supports Dr. Pagano's reasoning EXCEPT: ['Experimental evidence suggests that the checkerspot butterfly can adapt easily to a wide range of temperatures and geographic conditions.', 'Climate does not affect checkerspot butterflies themselves directly, but the plants they depend on thrive best in warm climates.', 'Several studies have shown that several other species of butterfly closely related to the checkerspot butterfly survive only in warm climates.', 'Checkerspot butterfly colonies observed under laboratory conditions are critically affected by small temperature changes.']