Ecology 6th Edition by Charles Krebs

Exercise 7

Hutchins (1947) set out a simple but elegant hypothesis that the geographic limits of marine species are set by thermal tolerances of the most sensitive life history stage. Thus species are limited by intolerance to cold at the poleward limit and by intolerance of heat at their equatorial limit. Discuss what factors might invalidate this hypothesis. Wethey (2002) discussed this issue for barnacles.