American Society of Naturalists

A membership society whose goal is to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences.

“Ecological pleiotropy suppresses the dynamic feedback generated by a rapidly changing trait”

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John P. DeLong

Ecological pleiotropy suppresses the dynamic feedback generated by a rapidly changing trait

<i>Didinium nasutum</i> consuming a <i>Paramecium caudatum</i>.<br />(Credit: John P. DeLong)
Didinium nasutum consuming a Paramecium caudatum.
(Credit: John P. DeLong)

It has long been assumed that evolution is too slow to influence short-term ecological dynamics. More recently, there is growing recognition that not only can traits evolve rather quickly, but their evolution can feed back into the processes generating dynamics. Thus, ecological dynamics may look different when evolution occurs—a process known generally as eco-evolutionary dynamics. But changing traits may influence the ecological dynamics in more than one way. If so, different feedback signals could cancel out or amplify each other, an effect called ecological pleiotropy. John DeLong of the University of Nebraska–Lincoln has recently found evidence for the cancellation of feedback signals in the classic protist predator-prey system of Didinium nasutum foraging on Paramecium Aurelia. Large (tenfold) changes in the predator’s cell volume accompanied the predator-prey cycle, but there was no detectable feedback to the population dynamics. Predator cell volume affects multiple aspects of this predator-prey interaction, and each of these aspects on their own would cause some shift in the dynamics of the system. Yet when taken together, there was nearly a complete suppression of the feedback to the predator-prey dynamics. Thus, even when evolution alters ecological interactions, detecting the downstream ecological consequences depends on the net effects of different types of feedback. Read the Article