evolutionary perspective is that the yard-sticks
used to measure community performance differ
from those relevant to evolutionary biology. Com-
munity properties most often used include produc-
tivity, carbon storage, nutrient acquisition or
decomposition rate, all of which are related to com-
munity functioning. Others reflect community
properties desirable for nature management such
as species diversity, community stability and resil-
ience. Although such properties can certainly de-
rive from species composition and individual
performance, they are not the primary targets of
natural selection. Rather, from an evolutionary
point of view, they are by-products of the competi-
tive and mutualistic interactions between indivi-
duals under selection to enhance their own fitness.
This discrepancy in views has led community biol-
ogists to discard individual variation and selection
in favour of a more phenomenological approach,
whereas it has caused evolutionary biologists to
turn away from community ecology because of its
descriptive nature. The value of a synthesis be-
tween community ecology and evolutionary biolo-
gy will hence critically depend on the potential for
common standards.
In this chapter, I aim to outline a newly emerging
field of research: evolutionary community ecology.
I will argue that considering variation in traits of
individuals and species is essential to understand
and predict community functioning and composi-
tion, and, vice versa, that community composition
is a key component of the selective forces determin-
ing genetic and phenotypic variation at the individ-
ual level. Bridging the gaps between community
and evolutionary ecology can be mutually benefi-
cial. In fact, we may even need an integrative ap-
proach in order to face fast changing environmental
conditions such as global warming and urbaniza-
tion, which pose ecological as well as evolutionary
challenges.
I will first review the main principles regarding
genetic and phenotypic variation from evolution-
ary biology, including maintenance of genetic di-
versity, measuring genetic variation and
phenotypic plasticity. I will emphasize parallels
between genetic diversity and species diversity,
and population and community ecology, respec-
tively. I will show as a proof of principle that com-
munity properties result from variation and
selection at the level of individual organisms. Sub-
sequently, I will address how variation in one spe-
cies mediates interaction at higher trophic levels or
at lower trophic levels. I will focus specifically on
two aspects of evolutionary community ecology: (1)
how genetic diversity and phenotypic plasticity of
single species influence the composition of commu-
nities and (2) how species diversity and composi-
tion in a community influence the genetic diversity
and realized phenotype of single species.
This chapter will not go into research on macro-
evolutionary timescales such as community phylo-
genetics and co-diversification of communities.
Even though evolutionary history can moderate
community assembly, I will focus on the shorter
timescale interactions as these are the most impor-
tant ones to cope with the ever-changing environ-
mental dynamics.11.2 Evolutionary biology: mechanisms for genetic and phenotypic change
Evolutionary ecologists study the cause and effect
of variation in fitness-related traits of individuals
such as longevity, fecundity and feeding rate in
their natural environment. They lean heavily on
the robust framework provided by quantitative
and population genetics for quantitative prediction
of evolutionary change. The two main topics that
can be identified are maintenance of genetic varia-
tion and the population benefits of variation. In
other words, how does natural selection act on
phenotypes while still preserving genetic diversity,
and does variation in phenotype affect performance
of an individual and its associated population? Un-
derstanding these processes at the population level
may allow us to extrapolate the consequences of
genetic diversity to community level and may illus-
trate its effect on community properties.11.2.1 Benefits and maintenance of genetic diversity at the population level
The population-level consequences of genetic vari-
ation have been the domain of evolutionary biolo-
gists for decades. Genetic variation can be
generated through sexual reproduction and the152 FUTURE DIRECTIONS