Biology subjects

Santostefano, F.

Publications and source records attributed to Santostefano, F..

3 recordsLinked to original sources

bioRxiv2025

Quantitative genetics of shy-bold behaviour and plastic response to novel predator cues in the cherry shrimp, Neocaridina davidi

Understanding the genetic basis of behavioural variation among-individuals is vital for predicting if, when, and how quickly behaviour can evolve under selection. However, in heterogeneous environments, behavioural plasticity (a source of within-individual variation) may also contribute to the phenotypic variance that can be selected on. If so, a complete picture of evolutionary potential, requires estimation of genotype-by-environment interactions (GxE). Here we investigate the quantitative genetics of shy-bold behavioural variation in the red cherry shrimp, Neocaridina davidi, an emerging decapod model for behavioural, genetic, and ecotoxicological research. Using a suite of behaviours associated with shy-bold personality variation we demonstrate moderate to high behavioural repeatabilities and show how a multivariate approach allows characterising the shape, not just the amount, of variation. Using a half-sib full sib breeding design in which shrimp from known families were tested under either control conditions or with predator (fish) cues present, we jointly estimate the plastic response to elevated risk, and the contribution of genetic factors to phenotypic variance. We find that genetic variance does underpin among-individual differences in behaviour. We also find evidence of plasticity, with individual shrimp shifting towards a shyer, or more risk averse, average phenotype in the presence of fish cues. However, we found no variation in plasticity either among-individuals (IxE) or among-genotypes (GxE). This implies that average behaviour can evolve under predator-mediated selection, but further adaptive evolution of behavioural plasticity may be constrained by a lack of GxE.

evolutionary biology↗

bioRxiv2024

Prey movement shapes the acquisition of predator expertise in a virtual bi-trophic system

The acquisition of expertise is crucial for predators to be successful hunters. To achieve this, predators must hone their skills and gain knowledge through repeated and extensive practice. On the other hand, prey may hinder the acquisition of predator expertise by employing antipredator tactics to evade detection and pursuit. However, empirical evidence on how predators acquire expertise through repeated encounters with their prey remains limited, largely due to the challenges of monitoring direct interactions in the wild. Here, we use a virtual predator-prey system (the game Dead by Daylight) to investigate how experience shapes individual and population hunting success in human predators across repeated interactions with their prey. We show that predators optimized prey consumption as they gained experience, indicating that they acquired expertise through extensive practice. At the population-level, we found that faster prey impaired the acquisition of expertise by reducing hunting success. Prey speed was also an important mediator of this relationship at the individual level, driving differences among predators in the acquisition of expertise. Our study outlines how prey antipredator behaviour can mediate the acquisition of expertise in predator populations.

ecology↗

bioRxiv2024

Indirect genetic effects increase the heritable variation available to selection and are largest for behaviours: a meta-analysis

The evolutionary potential of traits is governed by the amount of heritable variation available to selection. While this is typically quantified based on genetic variation in a focal individual for its own traits (direct genetic effects, DGEs), when social interactions occur, genetic variation in interacting partners can influence a focal individuals traits (indirect genetic effects, IGEs). Theory and studies on domesticated species have suggested IGEs can greatly impact evolutionary trajectories, but whether this is true more broadly remains unclear. Here we perform a systematic review and meta-analysis to quantify the amount of trait variance explained by IGEs and the contribution of IGEs to predictions of adaptive potential. We identified 180 effect sizes from 47 studies across 21 species and found that, on average, IGEs of a single social partner account for a small but statistically significant amount of phenotypic variation (0.03). As IGEs affect the trait values of each interacting group member and due to a typically positive - although statistically nonsignificant - correlation with DGEs (rDGE-IGE = 0.26), IGEs ultimately increase trait heritability substantially from 0.27 (narrow-sense heritability) to 0.45 (total heritable variance). This 66% average increase in heritability suggests IGEs can increase the amount of genetic variation available to selection. Furthermore, whilst showing considerable variation across studies, IGEs were most prominent for behaviours, and to a lesser extent for reproduction and survival, in contrast to morphological, metabolic, physiological, and development traits. Our meta-analysis therefore shows that IGEs tend to enhance the evolutionary potential of traits, especially for those tightly related to interactions with other individuals such as behaviour and reproduction. Lay SummaryPredicting evolutionary change is important for breeding better livestock and crops, for understanding how biodiversity arises and how populations respond to environmental change. Normally, these predictions are based on how the genetic variants in an organism influence its own traits (characteristics). However, when organisms socially interact, for instance by fighting or cooperating, then the genes in one individual can influence the traits of others, therefore affecting the potential for evolutionary change. We compared 47 studies across 21 animal species and found that the effect of the genes of a single social partner is small but statistically significant, while the total contribution of social genetic effects to evolutionary potential is large. These effects are particularly important for the evolution of animals behaviours and reproductive traits, but less so for other traits such as body size and physiology. We also found that, because an individual can interact with many others and influence them all, social interactions can substantially increase the potential for a population to evolve from generation to generation. Our results show how social interactions can potentially alter the evolution of those traits known to respond to social interactions in comparison to standard expectations.

evolutionary biology↗