Drafts by Etienne Danchin
We confront the core neoDarwinian tenet of blind variation, or random mutation, with classical a... more We confront the core neoDarwinian tenet of blind variation, or random mutation, with classical and recent models of genetic assimilation. We first argue that all the mechanisms proposed so far rely on blind genetic variation fueling natural selection. Then, we examine a new hypothetical mechanism of genetic assimilation, relying on nonblind genetic variation. Yet, we show that such a model still relies on blind variation of some sort to explain adaptation. Last, we discuss the very meaning of the tenet of blind variation. We propose a formal characterization of the tenet and argue that it should not be understood solely as an empirical claim, but also as a core explanatory principle.
Papers by Etienne Danchin
Biological Reviews, Sep 29, 2022
ABSTRACTAlthough conformity as a major driver for human cultural evolution is a well‐accepted and... more ABSTRACTAlthough conformity as a major driver for human cultural evolution is a well‐accepted and intensely studied phenomenon, its importance for non‐human animal culture has been largely overlooked until recently. This limited for decades the possibility of studying the roots of human culture. Here, we provide a historical review of the study of conformity in both humans and non‐human animals. We identify gaps in knowledge and propose an evolutionary route towards the sophisticated cultural processes that characterize humanity. A landmark in the study of conformity is Solomon Asch's famous experiment on humans in 1955. By contrast, interest in conformity among evolutionary biologists has only become salient since the turn of the new millennium. A striking result of our review is that, although studies of conformity have examined many biological contexts, only one looked at mate choice. This is surprising because mate choice is probably the only context in which conformity has self‐reinforcing advantages across generations. Within a metapopulation, i.e. a group of subpopulations connected by dispersing individuals, dispersers able to conform to the local preference for a given type of mate have a strong and multigenerational fitness advantage. This is because once females within one subpopulation locally show a bias for one type of males, immigrant females who do not conform to the local trend have sons, grandsons, etc. of the non‐preferred phenotype, which negatively and cumulatively affects fitness over generations in a process reminiscent of the Fisher runaway process. This led us to suggest a sex‐driven origin of conformity, indicating a possible evolutionary route towards animal and human culture that is rooted in the basic, and thus ancient, social constraints acting on mating preferences within a metapopulation. In a generic model, we show that dispersal among subpopulations within a metapopulation can effectively maintain independent Fisher runaway processes within subpopulations, while favouring the evolution of social learning and conformity at the metapopulation scale; both being essential for the evolution of long‐lasting local traditions. The proposed evolutionary route to social learning and conformity casts surprising light on one of the major processes that much later participated in making us human. We further highlight several research avenues to define the spectrum of conformity better, and to account for its complexity. Future studies of conformity should incorporate experimental manipulation of group majority. We also encourage the study of potential links between conformity and mate copying, animal aggregations, and collective actions. Moreover, validation of the sex‐driven origin of conformity will rest on the capacity of human and evolutionary sciences to investigate jointly the origin of social learning and conformity. This constitutes a stimulating common agenda and militates for a rapprochement between these two currently largely independent research areas.
Behavioral Ecology, Sep 24, 2020
Behavioural Processes, Apr 1, 2016
Philosophical Transactions of the Royal Society B: Biological Sciences, 2021
Cultural evolution requires the social transmission of information. For this reason, scholars hav... more Cultural evolution requires the social transmission of information. For this reason, scholars have emphasized social learning when explaining how and why culture evolves. Yet cultural evolution results from many mechanisms operating in concert. Here, we argue that the emphasis on social learning has distracted scholars from appreciating both the full range of mechanisms contributing to cultural evolution and how interactions among those mechanisms and other factors affect the output of cultural evolution. We examine understudied mechanisms and other factors and call for a more inclusive programme of investigation that probes multiple levels of the organization, spanning the neural, cognitive-behavioural and populational levels. To guide our discussion, we focus on factors involved in three core topics of cultural evolution: the emergence of culture, the emergence of cumulative cultural evolution and the design of cultural traits. Studying mechanisms across levels can add explanatory...
Biological Journal of the Linnean Society, 2019
Inbreeding, i.e. the mating of genetically related individuals, can lead to reduced fitness and i... more Inbreeding, i.e. the mating of genetically related individuals, can lead to reduced fitness and is considered to be a major selective force of mate choice. Although inbreeding avoidance has been found in numerous taxa, individuals may face constraints when pairing, leading to mating with suboptimal partners. In such circumstances, individuals that are able to avoid factors exacerbating detrimental effects of inbreeding should be favoured. Using the socially and genetically monogamous black-legged kittiwake (Rissa tridactyla), we explored whether the detrimental effects of inbreeding are exacerbated by sperm ageing (i.e. the post-meiotic senescence of sperm cells, mainly occurring within the female tracts after copulation), and whether they can be mitigated by behavioural tactics. First, by experimentally manipulating the age of the fertilizing sperm, we found that hatching failure due to sperm ageing increased with higher genetic similarity between mates. We then investigated whethe...
Animal Behaviour, Nov 1, 2016
Mate choice can strongly affect fitness in sexually reproducing organisms. A form of mate choice ... more Mate choice can strongly affect fitness in sexually reproducing organisms. A form of mate choice is mate copying, in which individuals use information about potential mates by copying the mate choice of other individuals. While many studies have documented mate copying, little is known about the effect of environmental conditions on this behaviour. Here, we report the first evidence that Drosophila melanogaster females can acquire a sexual preference for one male characteristic after witnessing a single mate choice event (i.e. speed learning). We also found that mate copying was correlated with air pressure and air pressure changes, so that females copied far more when air pressure was high and increasing, i.e. in good and improving weather conditions. These results reveal a quick social observational learning and highlight the potential importance of meteorological conditions for mate copying, a trait potentially driving reproductive isolation.
Trends in Ecology & Evolution, 2021
Science, 2004
Psychologists, economists, and advertising moguls have long known that human decision-making is s... more Psychologists, economists, and advertising moguls have long known that human decision-making is strongly influenced by the behavior of others. A rapidly accumulating body of evidence suggests that the same is true in animals. Individuals can use information arising from cues inadvertently produced by the behavior of other individuals with similar requirements. Many of these cues provide public information about the quality of alternatives. The use of public information is taxonomically widespread and can enhance fitness. Public information can lead to cultural evolution, which we suggest may then affect biological evolution.
Science, 2019
Thornquist and Crickmore claim that systematic experimental error may explain the results of Danc... more Thornquist and Crickmore claim that systematic experimental error may explain the results of Danchin and colleagues. Their claim rests on mistakes in their analyses, for which we provide corrections. We reassert that conformity in fruitflies predicts long-lasting mate-preference traditions.
Oxford Scholarship Online, 2017
This chapter confronts the neo-Darwinian core tenet of blind variation, or random mutation, with ... more This chapter confronts the neo-Darwinian core tenet of blind variation, or random mutation, with classical and recent models of genetic assimilation. We first argue that all the mechanisms proposed so far rely on blind genetic variation fueling natural selection. Then, we examine a new hypothetical mechanism of genetic assimilation, relying on nonblind genetic variation. Yet, we show that such a model still relies on blind variation of some sort to explain adaptation. Last, we discuss the very meaning of the tenet of blind variation. We propose a formal characterization of the tenet and argue that it should not be understood solely as an empirical claim, but also as a core explanatory principle.
The Journal of physiology, 2014
Physiology and evolutionary biology have developed as two separated disciplines, a separation tha... more Physiology and evolutionary biology have developed as two separated disciplines, a separation that mirrored the hypothesis that the physiological and evolutionary processes could be decoupled. We argue that non-genetic inheritance shatters the frontier between physiology and evolution, and leads to the coupling of physiological and evolutionary processes to a point where there exists a continuum between accommodation by phenotypic plasticity and adaptation by natural selection. This approach is also profoundly affecting the definition of the concept of phenotypic plasticity, which should now be envisaged as a multi-scale concept. We further suggest that inclusive inheritance provides a quantitative way to help bridging infra-individual (i.e. physiology) with supra-individual (i.e. evolution) approaches, in a way that should help building the long sough inclusive evolutionary synthesis.
Philosophical Transactions of the Royal Society B: Biological Sciences, 2019
Recent discoveries show that early in life effects often have long-lasting influences, sometimes ... more Recent discoveries show that early in life effects often have long-lasting influences, sometimes even spanning several generations. Such intergenerational effects of early life events appear not easily reconcilable with strict genetic inheritance. However, an integrative evolutionary medicine of early life effects needs a sound view of inheritance in development and evolution. Here, we show how to articulate the gene-centred and non-gene-centred visions of inheritance. We first recall the coexistence of two gene concepts in scientific discussions, a statistical one (focused on patterns of parent–offspring resemblance, and implicitly including non-DNA-sequence-based resemblance), and a molecular one (based on the DNA sequence). We then show how all the different mechanisms of inheritance recently discovered can be integrated into an inclusive theory of evolution where different mechanisms would enable adaptation to changing environments at different timescales. One surprising consequ...
Frédéric Mery,1,2,7 Susana A.M. Varela,3,4,7 Étienne Danchin,3,4,* Simon Blanchet,4 Deseada Parej... more Frédéric Mery,1,2,7 Susana A.M. Varela,3,4,7 Étienne Danchin,3,4,* Simon Blanchet,4 Deseada Parejo,5 Isabelle Coolen,4 and Richard H. Wagner6 1Laboratoire Évolution, Génomes et Spéciation UPR 9034, CNRS 91198 Gif-sur-Yvette, Cedex France 2Université Paris-Sud 11 91405 Orsay, Cedex France 3Université Pierre et Marie Curie Laboratoire ‘‘Fonctionnement et Évolution des Systèmes Écologiques’’ CNRS–UMR 7625, Bât. A, 7e Étage 7 quai Saint-Bernard, Case 237 F-75252 Paris, Cedex 05 France 4Université de Toulouse UPS Laboratoire d’Évolution et Diversité Biologique (EDB) CNRS–UMR 5174 118 Route de Narbonne, Bât. 4R3 31062 Toulouse, Cedex 9 France 5Department of Functional and Evolutionary Ecology Estación Experimental de Zonas Áridas, CSIC c/ General Segura 1 04001 Almerı́a Spain 6Konrad Lorenz Institute for Ethology Austrian Academy of Sciences Savoyenstrasse 1a A-1160 Vienna Austria
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Drafts by Etienne Danchin
Papers by Etienne Danchin