FIGURE 3.

The microbiome as an environmental component for the host. (A) Top: Schematic representation of a transition from the regular external environment toward a new stressful environmental state (E→Ẽ). The effective environmental state (green) is the sum of all the environmental influences on the host, taking into accounts the external conditions and internal inputs from the microbiome. An example of one possible trace of effective environmental state is shown in green. Bottom: Schematic representation of a potential host response with and without contribution of microbial disruption by the external environment (green and dotted red, respectively). Disruption of the microbiome can increase the response of the host, leading to a potentially faster and more pronounced response which is also more diverse and affects more individuals. (B) Same as (A) when the environment reverts back (Ẽ→E) within generation.