Biology subjects

Gulisija, D.

Publications and source records attributed to Gulisija, D..

4 recordsLinked to original sources

bioRxiv2026

Eco-evolutionary Dynamics of Colonization: When Does Source Selection Matter?

Ancestral balancing selection may facilitate evolutionary rescue following migration into a new habitat by providing founder populations with adaptive alleles, even when those alleles were not the fittest in the ancestral habitat. However, recent studies emphasize the roles of immigration history and admixture on colonization success. The extent to which balanced polymorphism may contribute to colonization success and the conditions under which it matters remain unclear. We use computer simulations to investigate how the mode of selection in the source population influences colonization success in new habitats under eco-evolutionary population dynamics, different invasion scenarios, and different selection regimes in the new habitat. We model source populations under balancing selection, directional selection, and neutrality, and allow founder groups of different sizes to invade a novel stable or perturbed habitat. We find that balancing selection in ancestral populations leads to higher rates of establishment in new habitats than are observed under source neutrality or directional selection when founder populations are relatively small, which would occur with a population bottleneck. This trend is observed regardless of whether invaders experience stable or variable conditions in a new habitat and persists under increasingly harsh conditions or greater environmental perturbations. When the colonizing populations are large, selection in the source population has little effect on invasion success. This study elucidates the interaction between genetic diversity and propagule pressure on colonization success, highlighting the number of adaptive alleles as a unique metric.

genetics↗

bioRxiv2025

Rapid Rescue: Spatial Storage Effect Facilitates Evolutionary Rescue in Rapidly Changing Environments

The storage effect is a plausible natural mechanism that generates balanced genetic polymorphism in varying environments. Balanced polymorphism may facilitate evolutionary rescue, promoting the persistence of populations otherwise destined for extinction. However, it is unknown whether the storage effect can be established in small populations whose size is allowed to vary, and if so, whether it will lead to evolutionary rescue. In this study, we investigate if the spatial storage effect emerges and facilitates evolutionary rescue across small populations of variable sizes that inhabit heterogeneous temporally varying environments and exchange migrants. We use an eco-evolutionary model to examine the phenomenon under a wide set of conditions, including the magnitudes and periods of temporal variation, habitat harshness, migration rates, the degrees of spatial heterogeneity, and increasing fitness oscillations over time, all within the framework of the logistic population growth model. We find that the storage effect emerges and that it increases the persistence of populations in harsh temporally varying habitats beyond levels driven by migration alone under source-sink dynamics. This mechanism, which we call "rapid rescue" broadens the known conditions for population persistence in the face of sudden environmental change.

evolutionary biology↗

bioRxiv2024

The evolutionary cost of homophily: social stratification facilitates stable variant coexistence and increased rates of evolution in host-associated pathogens

Coexistence of multiple strains of a pathogen in a host population can present significant challenges to vaccine development or treatment efficacy. Here we discuss a novel mechanism that can increase rates of long-lived strain polymorphism, rooted in the presence of social structure in a host population. We show that social preference of interaction, in conjunction with differences in immunity between host subgroups, can exert varying selection pressure on pathogen strains, creating a balancing mechanism that supports stable viral coexistence, independent of other known mechanisms. We use population genetic models to study rates of pathogen heterozygosity as a function of population size, host population composition, mutant strain fitness differences and host social preferences of interaction. We also show that even small periodic epochs of host population stratification can lead to elevated strain coexistence. These results are robust to varying social preferences of interaction, overall differences in strain fitnesses, and spatial heterogeneity in host population composition. Our results highlight the role of host population social stratification in increasing rates of pathogen strain diversity, with effects that should be considered when designing policies or treatments with a long-term view of curbing pathogen evolution.

evolutionary biology↗

bioRxiv2016

Phenotypic plasticity promotes recombination and gene clustering in periodic environments

The impact of changing environments on the evolution of genetic recombination is still unclear. While the Red Queen hypothesis provides a reasonable explanation for recombination, it requires coevolution with antagonistic species, such as host-parasite systems. We present a novel scenario for the evolution of recombination in changing environments: the genomic storage effect due to phenotypic plasticity. Using an analytic approximation and Monte Carlo simulations, we demonstrate that recombination evolves between a target locus that determines fitness, and a modifier locus that modulates the effects of alleles at the target. Evolution of recombination by this plasticity effect does not require antagonistic inter-specific interactions and, unlike in previous models, it occurs when only one target locus codes for a trait under selection. Furthermore, if the effects of multiple target loci are modified by the same plasticity locus, then the recombination rate among the target loci will tend to decrease, clustering the loci that influence a trait. These results provide a novel scenario for the evolution of recombination, highlighting the importance of phenotypic plasticity for recombination modification.

evolutionary biology↗