If a population is extremely sensitive to environmental conditions, even a small change in the environment can spell disaster for the population.
If a population declines suddenly and the only changes noted have been environmental fluctuations, the cause of the decline is most likely associated with these conditions.
Sudden changes in environmentally sensitive populations can be indicators of environmental problems that go beyond the species in question.
This breed is called metamorphic rocks - rocks formed in the Earth's crust as a result of metamorphism, ie the change of sedimentary and igneous rocks due to changes in physical and chemical conditions
