Disruptive selection occurs when there are very specific advantages for a species to be adapted to. From my lesson plan an example could be the rock pocket mouse. There are very light substrates (sandy) and very dark ones (lava flows). There is an advantage to being very light or very dark but inbetween serves no real advantage to blending in.
Flegr, J. (2009). Selection: disruptive, selective and directional. Retrieved from http://www.frozenevolution.com/selection-disruptive-stabilizing-and-directional
Taggart, R. (n.d.) Modes of selection. Retrieved from http://taggart.glg.msu.edu/isb200/select.htm