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Araújo Marreiro Varela, Susana

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Now showing 1 - 4 of 4
  • Social learning by mate‐choice copying increases dispersal and reduces local adaptation
    Publication . Sapage, Manuel; Varela, Susana.A.M.; Kokko, Hanna
    Abstract 1. In heterogeneous environments, dispersal may be hampered not only by direct costs, but also because immigrants may be locally maladapted. While maladaptation affects both sexes, this cost may be modulated in females if they express mate preferences that are either adaptive or maladaptive in the new local population. 2. Dispersal costs under local adaptation may be mitigated if it is possible to switch to expressing traits of locally adapted residents. In a sexual selection context, immigrant females may learn to mate with locally favoured males. Mate-choice copying is a type of social learning, where individuals, usually females, update their mating preferences after observing others mate. If it allows immigrant females to switch from maladapted to locally adapted preferences, their dispersal costs are mitigated as mate choice helps them create locally adapted offspring. 3. To study if copying can promote the evolution of dispersal, we created an individual- based model to simulate the coevolution of four traits: copying, dispersal, a trait relevant for local adaptation, and female preference. We contrast two scenarios with copying—either unconditional or conditional such that only dispersers copy—with a control scenario that lacks any copying. 4. We show copying to lead to higher dispersal, especially if copying is conditionally expressed. This leads to an increase in gene flow between patches and, consequently, a decrease in local adaptation and trait-preference correlations. 5. While our study is phrased with female preference as the learned trait, one may generally expect social learning to mitigate dispersal costs, with consequent feedback effects on the spatial dynamics of adaptation.
  • Sex differences in social buffering and social contagion of alarm responses in zebrafish
    Publication . Akinrinade, Ibukun; Varela, Susana.A.M.; Oliveira, Rui Filipe
    The alarm substance in fsh is a pheromone released by injured individuals after a predator attack. When detected by other fsh, it triggers fear/defensive responses, such as freezing and erratic movement behaviours. Such responses can also help other fsh in the shoal to modulate their own behaviours: decreasing a fear response if conspecifcs have not detected the alarm substance (social bufering) or triggering a fear response if conspecifcs detected the alarm substance (social contagion). Response variation to these social phenomena is likely to depend on sex. Because males have higher-risk life-history strategies than females, they may respond more to social bufering where they risk not responding to a real predator attack, while females should respond more to social contagion because they only risk responding to a false alarm. Using zebrafsh, we explored how the response of males and females to the presence/absence of the alarm substance is modifed by the alarmed/ unalarmed behaviour of an adjacent shoal of conspecifcs. We found that, in social bufering, males decreased freezing more than females as expected, but in social contagion males also responded more than females by freezing at a higher intensity. Males were, therefore, more sensitive to visual information, while females responded more to the alarm substance itself. Because visual information updates faster than chemical information, males took more risks but potentially more benefts as well, because a quicker adjustment of a fear response allows to save energy to other activities. These sex diferences provide insight into the modifying efect of life-history strategies on the use of social information.
  • Interaction time with conspecifics induces food preference or aversion in the wild Algerian mouse
    Publication . Andrade, Rita S.; Cerveira, Ana M.; M.L., Mathias; Varela, Susana.A.M.
    The social transmission of a novel food preference can avoid unnecessary costs arising from tasting nonedible foods. This type of social learning has been demonstrated in laboratory rats and mice. However, among wild animals, there may be several constraints that make it less effective. Using wild Algerian mice (Mus spretus) tested in the laboratory, we demonstrate that a preference for a novel food can be transmitted between Observer and Demonstrator individuals and that it is maintained for at least 30 days. However, only half of the Observers acquired a preference for the same food as the Demonstrators, and only when the duration of oronasal investigation was above a certain threshold (≥122 s); below this threshold (<122 s), Observers acquired a preference for the alternative food offered, which was maintained for a shorter time. Sex, size, and identity of individuals did not influence the transmission of social information. The results show that different interaction times will result in animals copying or avoiding the food choices of others. This suggests that the transmission of social information among wild animals is complex and probably influenced by many factors (e.g., dominance, familiarity, and health condition), ultimately conditioning the type of interaction between individuals and its outcome. Testing wild animals and the ecological and social constraints they face is, therefore, an important step in our understanding of how effectively social information is transmitted in nature.
  • Phenotypic architecture of sociality and its associated genetic polymorphisms in zebrafish
    Publication . Gonçalves, Claúdia; Kareklas, Kyriacos; Teles, Magda C; Varela, Susana.A.M.; Costa, João; Leite, Ricardo B.; Paixão, Tiago; Oliveira, Rui Filipe
    Sociality relies on motivational and cognitive components that may have evolved independently, or may have been linked by phenotypic correlations driven by a shared selective pressure for increased social competence. Furthermore, these components may be domain-specific or of general-domain across social and non-social contexts. Here, we used zebrafish to test if the motivational and cognitive components of social behavior are phenotypically linked and if they are domain specific or of general domain. The behavioral phenotyping of zebrafish in social and equivalent non-social tests shows that the motivational (preference) and cognitive (memory) components of sociality: (1) are independent from each other, hence not supporting the occurrence of a sociality syndrome; and (2) are phenotypically linked to non-social traits, forming two general behavioral modules, suggesting that sociality traits have been co-opted from general-domain motivational and cognitive traits. Moreover, the study of the association between single nucleotide polymorphisms (SNPs) and each behavioral module further supports this view, since several SNPs from a list of candidate “social” genes, are statistically associated with the motivational, but not with the cognitive, behavioral module. Together, these results support the occurrence of general-domain motivational and cognitive behavioral modules in zebrafish, which have been co-opted for the social domain. © 2022 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.