Biology subjects

Suswaram, M.

Publications and source records attributed to Suswaram, M..

3 recordsLinked to original sources

bioRxiv2022

Rising above the noise: The influence of populationdynamics on the evolution of acoustic signaling

Acoustic signaling is employed by many sexually reproducing species to select for mates and enhance fitness. However, signaling in dense populations can create an auditory background, or chorus, which can interfere with a signal receivers phonotactic selectivity, or the ability to distinguish signals. Feedback between the strength of an individuals signal, phonotactic selectivity, and population size, may interactin complex ways to impact the evolution of the signaling trait within a population, potentially leading to the emergence of silence. Here we formulate a general model that captures the dynamic feedback between individual acoustic signalers, phonotactic selectivity, and the populationlevel chorus to explore the eco-evolutionary dynamics of an acoustic trait. We find that population dynamics has a significant influence on the evolutionary dynamics of the signaling trait, and that very sharp transitions separate conspicuous from silent populations. Our framework also reveals that increased phonotactic selectivity promotes the stability of signaling populations. We suggest that understanding the relationship between factors influencing population size such as environmental productivity, as well as factors influencing phonotactic selectivity such as anthropogenic noise, are central to understanding the complex mosaic of acoustically signaling and silent populations.

evolutionary biology↗

bioRxiv2022

Parasitoid pressures and silence evolution

Acoustic signals used by organisms to attract mates are known to attract parasitoid flies. The parasitoid flies lay their eggs inside the host signaler, eventually killing the host. We build a host-parasitoid acoustic model to investigate the effect of parasitoid flies on the signalling hosts eco-evolutionary dynamics. We used field crickets as a system to build the framework of the model. We explore how the sex ratio and the female parasitoid fecundity impact the evolution of the acoustic signal and population density of the signalling hosts. We also explore the stability of the host populations with an increase in parasitoid load. We find that up to a threshold value, an increase in parasitoid load leads to a thriving yet silent host population. Consistent with field observations, we show how this emergence of silence as an evolutionary strategy is immediate. Our results show that a drastic increase in the parasitoid load can rapidly push the signalling host population towards instability and extinction.

evolutionary biology↗

bioRxiv2019

A sensory ecological perspective on mate sampling strategies: simulation models and an empirical test

Long-range communication signals play a central role in mate search and mate choice across a wide range of taxa. Among the different aspects of mate choice, the strategy an individual employ to search for potential mates (mate sampling) has been less explored despite its significance. Although analytical models of mate sampling have demonstrated significant differences in individual fitness returns for different sampling strategies, these models have rarely incorporated relevant information on the ecology of signalers and sensory physiology of receivers, both of which can profoundly influence which sampling strategy is optimal. In this study, we used simulation models to compare the costs and benefits of different female mate sampling strategies in an acoustically communicating field cricket (Plebeiogryllus guttiventris) by incorporating information on relative spacing of callers in natural choruses, their signal intensity and the effect of signal intensity on female phonotaxis behaviour. Mating with the louder caller that the female first approaches emerged as the optimal strategy, thus reflecting the importance of physiological mechanisms of sound signal localization (passive attraction) over active sampling. When tested empirically in the field, female behaviour was consistent with passive attraction.

evolutionary biology↗