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Ehlman SM, Scherer U, Wolf M. Developmental feedbacks and the emergence of individuality. ROYAL SOCIETY OPEN SCIENCE 2022; 9:221189. [PMID: 36465682 DOI: 10.6084/m9.figshare.c.6315476] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/07/2022] [Indexed: 05/24/2023]
Abstract
Behavioural individuality is a hallmark of animal life, with major consequences for fitness, ecology, and evolution. One of the most widely invoked explanations for this variation is that feedback loops between an animal's behaviour and its state (e.g. physiology, informational state, social rank, etc.) trigger and shape the development of individuality. Despite their often-cited importance, however, little is known about the ultimate causes of such feedbacks. Expanding on a previously employed model of adaptive behavioural development under uncertainty, we find that (i) behaviour-state feedbacks emerge as a direct consequence of adaptive behavioural development in particular selective environments and (ii) that the sign of these feedbacks, and thus the consequences for the development of behavioural individuality, can be directly predicted by the shape of the fitness function, with increasing fitness benefits giving rise to positive feedbacks and trait divergence and decreasing fitness benefits leading to negative feedbacks and trait convergence. Our findings provide a testable explanatory framework for the emergence of developmental feedbacks driving individuality and suggest that such feedbacks and their associated patterns of behavioural diversity are a direct consequence of adaptive behavioural development in particular selective environments.
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Affiliation(s)
- Sean M Ehlman
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Ulrike Scherer
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Max Wolf
- SCIoI Excellence Cluster, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
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Ehlman SM, Scherer U, Wolf M. Developmental feedbacks and the emergence of individuality. ROYAL SOCIETY OPEN SCIENCE 2022; 9:221189. [PMID: 36465682 PMCID: PMC9709565 DOI: 10.1098/rsos.221189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/07/2022] [Indexed: 05/08/2023]
Abstract
Behavioural individuality is a hallmark of animal life, with major consequences for fitness, ecology, and evolution. One of the most widely invoked explanations for this variation is that feedback loops between an animal's behaviour and its state (e.g. physiology, informational state, social rank, etc.) trigger and shape the development of individuality. Despite their often-cited importance, however, little is known about the ultimate causes of such feedbacks. Expanding on a previously employed model of adaptive behavioural development under uncertainty, we find that (i) behaviour-state feedbacks emerge as a direct consequence of adaptive behavioural development in particular selective environments and (ii) that the sign of these feedbacks, and thus the consequences for the development of behavioural individuality, can be directly predicted by the shape of the fitness function, with increasing fitness benefits giving rise to positive feedbacks and trait divergence and decreasing fitness benefits leading to negative feedbacks and trait convergence. Our findings provide a testable explanatory framework for the emergence of developmental feedbacks driving individuality and suggest that such feedbacks and their associated patterns of behavioural diversity are a direct consequence of adaptive behavioural development in particular selective environments.
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Affiliation(s)
- Sean M. Ehlman
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB – Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Ulrike Scherer
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB – Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Max Wolf
- SCIoI Excellence Cluster, Berlin, Germany
- IGB – Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
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Ehlman SM, Scherer U, Wolf M. Developmental feedbacks and the emergence of individuality. ROYAL SOCIETY OPEN SCIENCE 2022; 9:221189. [PMID: 36465682 DOI: 10.5281/zenodo.7299681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/07/2022] [Indexed: 05/24/2023]
Abstract
Behavioural individuality is a hallmark of animal life, with major consequences for fitness, ecology, and evolution. One of the most widely invoked explanations for this variation is that feedback loops between an animal's behaviour and its state (e.g. physiology, informational state, social rank, etc.) trigger and shape the development of individuality. Despite their often-cited importance, however, little is known about the ultimate causes of such feedbacks. Expanding on a previously employed model of adaptive behavioural development under uncertainty, we find that (i) behaviour-state feedbacks emerge as a direct consequence of adaptive behavioural development in particular selective environments and (ii) that the sign of these feedbacks, and thus the consequences for the development of behavioural individuality, can be directly predicted by the shape of the fitness function, with increasing fitness benefits giving rise to positive feedbacks and trait divergence and decreasing fitness benefits leading to negative feedbacks and trait convergence. Our findings provide a testable explanatory framework for the emergence of developmental feedbacks driving individuality and suggest that such feedbacks and their associated patterns of behavioural diversity are a direct consequence of adaptive behavioural development in particular selective environments.
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Affiliation(s)
- Sean M Ehlman
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Ulrike Scherer
- SCIoI Excellence Cluster, Berlin, Germany
- Humboldt University, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Max Wolf
- SCIoI Excellence Cluster, Berlin, Germany
- IGB - Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
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Kennedy P, Sumner S, Botha P, Welton NJ, Higginson AD, Radford AN. Diminishing returns drive altruists to help extended family. Nat Ecol Evol 2021; 5:468-479. [PMID: 33589803 PMCID: PMC7610556 DOI: 10.1038/s41559-020-01382-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 12/10/2020] [Indexed: 11/09/2022]
Abstract
Altruism between close relatives can be easily explained. However, paradoxes arise when organisms divert altruism towards more distantly related recipients. In some social insects, workers drift extensively between colonies and help raise less related foreign brood, seemingly reducing inclusive fitness. Since being highlighted by W. D. Hamilton, three hypotheses (bet hedging, indirect reciprocity and diminishing returns to cooperation) have been proposed for this surprising behaviour. Here, using inclusive fitness theory, we show that bet hedging and indirect reciprocity could only drive cooperative drifting under improbable conditions. However, diminishing returns to cooperation create a simple context in which sharing workers is adaptive. Using a longitudinal dataset comprising over a quarter of a million nest cell observations, we quantify cooperative payoffs in the Neotropical wasp Polistes canadensis, for which drifting occurs at high levels. As the worker-to-brood ratio rises in a worker's home colony, the predicted marginal benefit of a worker for expected colony productivity diminishes. Helping related colonies can allow effort to be focused on related brood that are more in need of care. Finally, we use simulations to show that cooperative drifting evolves under diminishing returns when dispersal is local, allowing altruists to focus their efforts on related recipients. Our results indicate the power of nonlinear fitness effects to shape social organization, and suggest that models of eusocial evolution should be extended to include neglected social interactions within colony networks.
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Affiliation(s)
- P. Kennedy
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK,Correspondence:
| | - S. Sumner
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - P. Botha
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - N. J. Welton
- Population Health Sciences, Bristol Medical School, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol, BS8 2PS, UK
| | - A. D. Higginson
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, EX4 4QG, UK
| | - A. N. Radford
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
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Pokhrel P, Bennett BL, Regmi S, Idrisov B, Galimov A, Akhmadeeva L, Sussman S. Individualism-Collectivism, Social Self-Control and Adolescent Substance Use and Risky Sexual Behavior. Subst Use Misuse 2018; 53:1057-1067. [PMID: 29161526 PMCID: PMC9292063 DOI: 10.1080/10826084.2017.1392983] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Individualism and collectivism are cultural syndromes that have been associated with adolescent problem behavior in studies conducted in the U.S. and Southeast Asia. However, research investigating the mechanisms of how cultural orientation impacts health risk behaviors has been limited. This study tested a new model explaining the relationship between cultural orientation (i.e., individualism, collectivism) and adolescent problem behavior (i.e., substance use and risky sex) in terms of interpersonal self-regulation (i.e., social self-control). As such, the study is rooted in theories of the role of culture in developing self-regulation. Participants were high school students (N = 716) from the Bashkirtostan Republic of the Russian Federation. Adolescents from the Russian Federation tend to show high prevalence of cigarette smoking and binge drinking. People of the Russian Federation in general are traditionally collectivist in orientation, although increased globalization and post-Soviet capitalism may indicate high individualist values in younger generation Russians. Using path analysis we found that in addition to having direct effects, higher individualism indirectly affected substance use and risky sexual behavior through social self-control and negative life events. Higher collectivism was found to have a direct protective effect on risky sexual behavior and a direct effect on social self-control. However, collectivism was not found to have indirect effects on substance use or risky sexual behavior. Higher individualism appears to function as a risk factor for adolescent problem behavior and this relationship may be mediated by lower social self-control. Culturally-tailored prevention programs utilizing the individualism-collectivism framework may benefit from addressing social self-control.
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Affiliation(s)
- Pallav Pokhrel
- a Cancer Prevention and Control Program , University of Hawaii Cancer Center , Honolulu , Hawaii , USA
| | - Brooke L Bennett
- a Cancer Prevention and Control Program , University of Hawaii Cancer Center , Honolulu , Hawaii , USA
| | - Sakshi Regmi
- b School of Public Health & Health Sciences , University of Massachusetts at Amherst , Amherst , Massachusetts , USA
| | - Bulat Idrisov
- c Bashkir State Medical University , Ufa , Russia.,d Boston University Medical Center , Boston , USA
| | - Artur Galimov
- e Institute for Health Promotion & Disease Prevention Research, Keck School of Medicine , University of Southern California , Los Angeles , California , USA
| | | | - Steve Sussman
- e Institute for Health Promotion & Disease Prevention Research, Keck School of Medicine , University of Southern California , Los Angeles , California , USA
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Sibly RM, Curnow RN. Genetic polymorphisms between altruism and selfishness close to the Hamilton threshold rb = c. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160649. [PMID: 28386424 PMCID: PMC5367295 DOI: 10.1098/rsos.160649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/11/2017] [Indexed: 06/07/2023]
Abstract
Genes that in certain conditions make their carriers altruistic are being identified, and altruism and selfishness have shown to be heritable in man. This raises the possibility that genetic polymorphisms for altruism/selfishness exist in man and other animals. Here we characterize some of the conditions in which genetic polymorphisms may occur. We show for dominant or recessive alleles how the positions of stable equilibria depend on the benefit to the recipient, b, and the cost to the altruist, c, for diploid altruists helping half or full sibs, and haplodiploid altruists helping sisters. Stable polymorphisms always occur close to the Hamilton threshold rb = c. The position of the stable equilibrium moves away 0 or 1 with both increases in c, the cost paid by the altruist, and increasing divergence from the Hamilton threshold, and alleles for selfishness can reach frequencies around 50%. We evaluate quantitative estimates of b, c and r from field studies in the light of these predictions, but the values do not fall in the regions where genetic polymorphisms are expected. Nevertheless, it will be interesting to see as genes for altruism are discovered whether they are accompanied by alternate alleles for selfishness.
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Affiliation(s)
- Richard M. Sibly
- School of Biological Sciences, University of Reading, Whiteknights, Reading RG6 6AS, UK
| | - Robert N. Curnow
- Department of Mathematics and Statistics, University of Reading, Whiteknights, Reading RG6 6AX, UK
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Sibly RM, Curnow RN. Evolution of discrimination in populations at equilibrium between selfishness and altruism. J Theor Biol 2012; 313:162-71. [PMID: 23010149 DOI: 10.1016/j.jtbi.2012.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 08/09/2012] [Accepted: 08/13/2012] [Indexed: 11/30/2022]
Abstract
Where there is genetically based variation in selfishness and altruism, as in man, altruists with an innate ability to recognise and thereby only help their altruistic relatives may evolve. Here we use diploid population genetic models to chart the evolution of genetically-based discrimination in populations initially in stable equilibrium between altruism and selfishness. The initial stable equilibria occur because help is assumed subject to diminishing returns. Similar results were obtained whether we used a model with two independently inherited loci, one controlling altruism the other discrimination, or a one locus model with three alleles. The latter is the opposite extreme to the first model, and can be thought of as involving complete linkage between two loci on the same chromosome. The introduction of discrimination reduced the benefits obtained by selfish individuals, more so as the number of discriminators increased, and selfishness was eventually eliminated in some cases. In others selfishness persisted and the evolutionary outcome was a stable equilibrium involving selfish individuals and both discriminating and non-discriminating altruists. Heritable variation in selfishness, altruism and discrimination is predicted to be particularly evident among full sibs. The suggested coexistence of these three genetic dispositions could explain widespread interest within human social groups as to who will and who will not help others. These predictions merit experimental and observational investigation by primatologists, anthropologists and psychologists.
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Affiliation(s)
- Richard M Sibly
- School of Biological Sciences, University of Reading, Whiteknights, Reading, UK.
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