Biology subjects

Bangerter, A.

Publications and source records attributed to Bangerter, A..

6 recordsLinked to original sources

bioRxiv2026

Phenotypic and Genomic Evidence of Adaptive Tracking in Thermal Tolerance of Wild Populations of an Invasive Drosophila.

Adaptive tracking is an evolutionary process in which allele frequencies and phenotypes shift in response to temporally fluctuating environments. Currently it is unclear whether adaptive tracking causes predictable evolution of complex traits such as thermal tolerance. We investigated seasonal adaptive tracking of critical thermal minimum (CTmin) and genome-wide allele frequencies over multiple years in the invasive fly Drosophila suzukii. CTmin increased throughout the growing season, showing a lag of several generations between increasing temperature and evolutionary change. Genetic analyses indicate CTmin is highly polygenic, with little overlap between alleles associated with CTmin and other seasonally fluctuating alleles. Thus, polygenic traits may track seasonal environments without leaving strong genomic signals. By contrast, there were strong seasonal genomic signatures for alleles associated with oligogenic traits as such pesticide resistance and olfactory behavior. These findings suggest that seasonal adaptive tracking shapes a broad suite of traits that contribute to D. suzukiis invasion success.

evolutionary biology↗

bioRxiv2024

Limited population structure but signals of recent selection in introduced African Fig Fly (Zaprionus indianus) in North America

Invasive species have devastating consequences for human health, food security, and the environment. Many invasive species adapt to new ecological niches following invasion, but little is known about the early steps of adaptation. Here we examine population genomics of a recently introduced drosophilid in North America, the African Fig Fly, Zaprionus indianus. This species is likely intolerant of subfreezing temperatures and recolonizes temperate environments yearly. We generated a new chromosome-level genome assembly for Z. indianus. Using resequencing of over 200 North American individuals collected over four years in temperate Virginia, plus a single collection from subtropical Florida, we tested for signatures of population structure and adaptation within invasive populations. We show founding populations are sometimes small and contain close genetic relatives, yet temporal population structure and differentiation of populations is mostly absent across North America. However, we identify two haplotypes that are differentiated between African and invasive populations and show signatures of selective sweeps. Both haplotypes contain genes in the cytochrome P450 pathway, indicating these sweeps may be related to pesticide resistance. X chromosome evolution in invasive populations is strikingly different from the autosomes, and a haplotype on the X chromosome that is highly differentiated between Virginia and Florida populations is a candidate for temperate adaptation. These results show that despite limited population structure, populations may rapidly evolve genetic differences early in an invasion. Further uncovering how these genomic regions influence invasive potential and success in new environments will advance our understanding of how organisms evolve in changing environments. Article SummaryInvasive species (organisms that have been moved outside their natural range by human activities) can cause problems for both humans and the environment. We studied the genomes of over 200 individuals of a newly invasive fruit fly in North America, the African Fig Fly. We found genetic evidence that these recently introduced flies may be evolving in their new environments, which could make them stronger competitors and more likely to become pests.

evolutionary biology↗

bioRxiv2024

Oxytocin and shared intentionality drive variation in cooperation in children

While humans cooperate with unrelated individuals to an extent that far outstrips any other species, we also display extreme variation in decisions about whether to cooperate or not. A diversity of cognitive, affective, social, and physiological mechanisms interact to shape these decisions. For example, group membership, shared intentionality talk (i.e. talk about shared goals), and natural initial oxytocin levels affect cooperation in adults in an optimal foraging paradigm that is loosely modelled on the iterated prisoners dilemma. In this egg hunt, shared intentionality talk was key to achieve cooperation, and it occurred more between participants who shared the same group membership and had higher initial oxytocin levels. Such complex interactions raise the question of the age at which humans develop the necessary mechanisms to cooperate effectively in the egg hunt game. Here, we tested children in secondary school aged between 10 and 14 years. We found that, as for adults, shared intentionality talk was crucial for successful cooperation. Furthermore, initial oxytocin levels affected cooperation through shared intentionality talk. In contrast, group membership did not affect behaviour. Finally, pre- and post-experiment oxytocin levels showed various interactions with group membership and gender. Thus, childrens performance was relatively similar to adults while showing some differences with respect to underlying mechanisms. Our study is a rare contribution to further our understanding of the role of oxytocin in early adolescent social behaviour.

developmental biology↗

bioRxiv2023

Chimpanzees and bonobos reinstate an interrupted triadic game

When humans engage in joint action, they seem to so with an underlying sense of joint commitment, a feeling of mutual obligation towards their partner and a shared goal. Whether our closest living relatives, bonobos and chimpanzees, experience and understand joint commitment in the same way is subject to debate. Crucial evidence concerns how participants respond to interruptions of joint actions, particularly if they protest or attempt to reengage their reluctant or distracted partners. During dyadic interactions, bonobos and chimpanzees appear to have some sense of joint commitment, according to recent studies. Yet, data are inconsistent for triadic games with objects. We addressed this issue by engaging N=23 apes (5 adult chimpanzees, 5 infant bonobos, 13 adult bonobos) in a "tug-of-war" game with a human experimenter who abruptly stopped playing. Adult apes readily attempted to reengage the experimenter (>60% of subjects on first trial), with no group differences in the way of reengagement. Infant bonobos rarely reengaged and never did so on their first trial. Importantly, when infants reengaged passive partners, they mostly deployed (tactile) signals, yet rarely game-related behaviours (GRBs) as commonly observed in adults. These findings might explain negative results of earlier research. Bonobos and chimpanzees may thus have motivational foundations for joint commitment, although this capacity might develop over lifetime. We discuss this finding in relation to evolutionary and developmental theories on joint commitment.

animal behavior and cognition↗

bioRxiv2022

A cosmopolitan inversion drives seasonal adaptation in overwintering Drosophila

Drosophila melanogaster living in temperate regions evolve as they track seasonal fluctuations. Yet, we lack an understanding of the genetic architecture of seasonal adaptive tracking. By sequencing orchard populations collected across multiple years, we characterized the genomic signal of seasonal demography and identified that the cosmopolitan inversion In(2L)t drives seasonal adaptation. In(2L)t shows footprints of selection that are inconsistent with simple explanations of genetic drift, as well as signatures of partial selective sweeps. A meta-analysis of phenotypic studies shows that seasonal loci within In(2L)t are associated with behavior, life-history, physiology, and morphology traits. Our results identify candidate regions that underlie seasonal adaptive tracking and link them to phenotype. This work supports the general hypothesis that inversions are important drivers of rapid adaptation. One-Sentence SummaryA chromosomal inversion drives adaptive evolution between seasons in wild fruit flies.

evolutionary biology↗

bioRxiv2020

Wild flies hedge their thermal preference bets in response to seasonal fluctuations

Fluctuating environmental pressures can challenge organisms by repeatedly shifting the optimum phenotype. Two contrasting evolutionary strategies to cope with these fluctuations are 1) evolution of the mean phenotype to follow the optimum (adaptive tracking) or 2) diversifying phenotypes so that at least some individuals have high fitness in the current fluctuation (bet-hedging). Bet-hedging could underlie stable differences in the behavior of individuals that are present even when genotype and environment are held constant. Instead of being simply noise, behavioral variation across individuals may reflect an evolutionary strategy of phenotype diversification. Using geographically diverse wild-derived fly strains and high-throughput assays of individual preference, we tested whether thermal preference variation in Drosophila melanogaster could reflect a bet-hedging strategy. We also looked for evidence that populations from different regions differentially adopt bet-hedging or adaptive-tracking strategies. Computational modeling predicted regional differences in the relative advantage of bet-hedging, and we found patterns consistent with that in regional variation in thermal preference heritability. In addition, we found that temporal patterns in mean preference support bet-hedging predictions and that there is a genetic basis for thermal preference variability. Our empirical results point to bet-hedging in thermal preference as a potentially important evolutionary strategy in wild populations.

evolutionary biology↗