Lecture 15: Coexistence

The discussion of the Lotka-Volterra model provides an oversimplified view of the world of competition — and suggests that more often than not, competition should lead to exclusion.  However, we routinely see communities comprised of similar species — today we’ll talk about several mechanisms that can lead to coexistence despite Lotka-Volterra dynamics.

    • Habitat and temporal heterogeneity can prevent superior competitor from ever excluding the inferior
    • frequent disturbance can permit a weaker competitor to persist via metapopualtion-like dynamics
    • r-selected species can take advantage of ephemeral gaps before exclusion by K-selected species
    • Aggregated distributions can intensify intra- compared to inter-specific competition
    • Competition can drive selection for changes in characteristics that minimize competition (e.g. character displacement)

The second homework assignment is due on 18 October by 5 PM.  The files are here, a word document with the questions, and an excel worksheet use to complete the questions:

Assignment 2

Homework 2 worksheet

Paper for section 2

Paper for section 3

Leave a Reply