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(
Etienne and Haegeman, 2011
). Extensions of the theory using population
genetic models have shown distributions of incipient species abundance in
between the two extremes of abundance (
de Aguiar et al., 2009; Kopp, 2010;
Meli
ยด
n et al., 2010
), but all these results have been developed exclusively
within one metacommunity (
Alonso et al., 2006; Beeravolu et al., 2009
).
Here, we propose an eco-evolutionary dynamics framework with explicit
genetic speciation for individual-based food webs that can be tested against
datasets ranging from individual diets and feeding rates to the macroecolo-
gical patterns of diversity in food webs (
Dunne, 2005; Wootton, 2005
).
By working at individual level, the consequences of limited samplings of
individual diets and species abundance in space and time, a classical con-
straint in food web studies (
Cohen, 1978; Nakazawa et al., 2011; Polis, 1991;
Woodward and Warren, 2007; Woodward et al., 2010
), can be analysed at
different levels of aggregations and we consider death in the context of
neutral theory as a fundamental process required for individuals to persist
(i.e. predation and metabolic requirements).
In order to link two interacting communities from individual processes, we
consider each death event is caused by a individual predator, and, in analogy
to the random encounter predator-prey models (
Lotka, 1956; Pascual, 2005
),
all individual predators are assumed to have equal feeding rates. In order to
minimize the complexity of the model to keep it testable, we then add sexual
reproduction as the main driver of genetic differentiation in the absence of
ecological niches. After adding pairwise sexual and trophic interactions to
the birth-death dynamics, we ask whether individual-based food webs driven
by genetic and ecological drift predict the individual number of prey per
individual predator, species abundance curves and species-level food web
connectance. Deviations from neutral expectation can tell us how much
ecological differentiation and ecological speciation do we need to improve
the fit to the observed data, and these expectations also set a baseline to
be improved by the addition of several mechanisms ranging from the con-
straints imposed by the ontogeny and growth of individuals (
De Roos, 2008
),
or foraging and metabolic theory (
Beckerman et al., 2006; Ings et al., 2009
)to
the addition of explicit niches and ecological speciation (
Post and Palkovacs,
2009; Schoener, 2011
).
The present study consists of three parts. In the first part, we describe in
detail how we combine the original neutral theory of biodiversity with a
DNA-sequence-based model that uses genetic-distance-based speciation and
sexual reproduction. We then add trophic interactions to this combined
model and we call it 'neutral eco-evolutionary dynamics model'. In the last
section of the first part, we derive the equations that describe the dynamics of
all these processes and the steps of the model that generate the number of
individual prey per individual predator, the species abundance curves for two
communities and the species-level food web connectance. In the second part,
