Translations:AY Honors/Ecology - Advanced/Answer Key/33/en
From Pathfinder Wiki
Shelford's Law of Tolerance
Shelford's Law of Tolerance states that a species' distribution is controlled by the environmental factors for which it has the narrowest tolerance. This law explains why a species is present in some areas, but absent in others. Remember that tolerance has both a lower limit and an upper limit - not enough or too much of a resource will limit a species' ability to survive. When any one of these factors exceeds the tolerance, the species will die out. Small - and even major - alterations to a creatures environment may or may not cause it to die. Survival depends on that creature's tolerance to the altered factor.
