Every person has their own part to play or if you want to get scientific then a niche. And if somebody doesn't do their job then it could slow everyone else down. Maybe I don't fully understand the question, But I hope its right.
Our genes can be affected by the environment and change the way our traits are displayed, called the phenotype. However, changes in phenotype have an underlying genotypic source. Epigenetics or epigenetic changes are changes in the way traits are expressed as an effect of the environment (i.e. food we ate, chemicals in the body, environmental stresses), without changes in the DNA. Simply put, in epigenetics, some parts of the DNA are turned on or off in response to environmental conditions.
It would destroy the population of some of the nests
Volcanic eruptions may occur in both locations, as the movement can cause the tectonic plates to allow magma through.