Advantages of storage in a fluctuating environment
Kooi, B.W. and Troost, T.A. 2006
Advantages of storage in a fluctuating environment.
Theor. Pop. Biol 70: 527 - 541
Abstract
We will elaborate the evolutionary course of an ecosystem consisting
of a population in a chemostat environment with periodically
fluctuating nutrient supply. The population consists of structural and
energy storage compartments. In a constant chemostat environment a
species without energy storage always out-competes a species with
energy reserves. This hampers evolution of species with storage from
those without storage. Using the adaptive dynamics approach for
non-equilibrium ecological systems we will show that in a fluctuating
environment there are multiple stable evolutionary singular strategies
(ss's): one for a species without, and one for a species with
energy storage. The evolutionary end-point depends on the initial
evolutionary state. We will formulate the invasion fitness in terms
of Floquet multipliers for the oscillating non-autonomous system.
Bifurcation theory is used to study points where due to evolutionary
development by mutational steps, the stability of the ecological
system changes qualitatively. In a constant environment there is a
unique stable equilibrium for one species following the ``competitive
exclusion'' principle. In contrast, in a fluctuating environment an
evolutionary branching point arises and two species may coexist. That
is, the non-equilibrium dynamics enhances biodiversity. However, we
show that this coexistence is not stable on the evolutionary time
scale and always a single species survives.