An Individual-Based Modeling Approach to Investigate Sympatric Speciation via Specialized Resource Usage

Abstract

An individual-based model, EcoSim, was employed to investigate if specialized resource use could promote sympatric speciation. Prey individuals in the original version of EcoSim were supplied with a single primary food resource. A dual resource version with different food resources (Food 1 and Food 2) was also developed to create favorable conditions for the emergence of specialized food consumption among prey individuals. The single resource version was used as the control to determine the impact of the presence of multiple food resources on the occurrence of sympatric speciation. Each unit of Food 2 contained a higher amount of energy than Food 1, and Food 1 was more accessible than Food 2. Initially, prey individuals mostly fed on Food 1. However, after the emergence of food specialization, the consumption rate of Food 2 significantly exceeded the consumption rate of Food 1; although prey individuals more frequently encountered Food 1. While sympatric speciation was observed in the dual resource version runs, we could not identify any sympatric species in the single resource version runs. Machine learning techniques were also employed to identify the most influential initial conditions leading to sympatric speciation. According to the obtained results, in most lineages sympatric speciation occurred at the beginning of the food specialization process. When the lineage had a high special diversity, the lineage needed two different criteria to diverge sympatrically: possessing high genetic diversity and a large population size. In support of previous findings, this study demonstrated that the most accurate determination of initial conditions leading to sympatric speciation can be obtained from lineages that are at the beginning of the divergence process. In conclusion, this study indicated that divergent foraging behavior could potentially lead to the sympatric emergence of new How to cite this paper: Pour, M.K., Bandehbahman, S., Gras, R. and Cristescu, M.E.

The Deep Past Controls the Phylogenetic Structure of Present, Local Communities

“…Zooming in to the fine scales relevant to community-level coexistence, dispersal is needed for species resulting from allopatric speciation to meet (Moen et al 2009). In a minority of situations involving sympatric speciation, coexistence can happen from the start, and dispersal often results in only one of the species occurring elsewhere (Pour et al 2017).…”

“…Nevertheless, very few specific studies relate the phylogenetic signal versus diversification of niches within lineages to other traits of these lineages. Basically, three types of explanations exist: (a) because adaptation is not needed (Pour et al 2017)-this may have to do with niche construction or phenotypic plasticity; (b) because adaptation is difficult (Crisp & Cook 2012) due to variation being constrained (genetic constraints, allometries, trade-offs, architectural constraints) (Futuyma 2010), nonselective (gene flow, neutral evolution), or lost due to specialization; or (c) because local adaptation is slower than species turnover, and so community assembly replaces adaptation (Ackerly 2003, Prinzing et al 2017.…”

Digital Evolution for Ecology Research: A Review

“…As a result, species gradually diverge from each other. EcoSim has been used for a variety of research on speciation (Golestani et al, 2012;Gras et al, 2015;Pour et al, 2017;Bhattacharjee et al, 2018), species area relationships (Devaurs and Gras, 2010;Mashayekhi et al, 2014b), and other ecological questions (Pour et al, 2015;Bhattacharjee et al, 2019;Scott and Gras, 2020).…”