scholarly journals Modeling long lifespans in eusocial insect populations

2018 ◽  
Author(s):  
Donepudi RaviTeja ◽  
Ramakrishna Ramaswamy
Keyword(s):  
Evolutionary Model ◽  
Dominant Strategy ◽  
Division Of Labour ◽  
Agent Based ◽  
Eusocial Insect ◽  
Extrinsic Mortality ◽  
Extended Lifespan ◽  
Evolution Of Eusociality ◽  
Eusocial Species ◽  
Migration Probability

AbstractAlong with division of labour, and life-history complexities, a characteristic of eusocial insect societies is the greatly extended lifespan for queens. The colony structure reduces the extrinsic mortality of the queen, and according to classical evolutionary theories of ageing, this greatly increases the lifespan. We explore the relationship between the evolution of longevity and the evolution of eusociality by introducing age-structure into a previously proposed evolutionary model and also define an associated agent-based model. A set of three population structures are defined: (i) solitary with all reproductive individuals, (ii) monogynous eusocial with a single queen, and (iii) polygynous eusocial, with multiple queens.In order to compare the relative fitnesses we compete all possible pairs of these strategies as well as all three together, analysing the effects of parameters such as the probability of progeny migration, group benefits, and extrinsic mortality on the evolution of long lifespans. Simulations suggest that long lifespans appear to evolve only in eusocial populations, and further, that long lifespans enlarge the region of parameter space where eusociality evolves. When all three population strategies compete, the agent-based simulations indicate that solitary strategies are largely confined to shorter lifespans. For long lifespan strategies the solitary behaviour results only for extreme (very low or very high) migration probability. For median and small values of migration probability, the polygynous eusocial and monogynous eusocial strategies give advantage to the population respectively. For a given migration probability, with an increase in lifespan, the dominant strategy changes from solitary to polygynous to monogynous eusociality. The evolution of a long lifespan is thus closely linked to the evolution of eusociality, and our results are in accord with the observation that the breeding female in monogynous eusocial species has a longer lifespan than those in solitary or polygynous eusocial species.

scholarly journals Cultural diversity and wisdom of crowds are mutually beneficial and evolutionarily stable

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benoît de Courson ◽  
Léo Fitouchi ◽  
Jean-Philippe Bouchaud ◽  
Michael Benzaquen
Keyword(s):  
Social Learning ◽  
Information Seeking ◽  
Information Quality ◽  
Evolutionary Model ◽  
Division Of Labour ◽  
Necessary Condition ◽  
Wisdom Of Crowds ◽  
Human Species ◽  
Evolutionarily Stable ◽  
Individual Information

AbstractThe ability to learn from others (social learning) is often deemed a cause of human species success. But if social learning is indeed more efficient (whether less costly or more accurate) than individual learning, it raises the question of why would anyone engage in individual information seeking, which is a necessary condition for social learning’s efficacy. We propose an evolutionary model solving this paradox, provided agents (i) aim not only at information quality but also vie for audience and prestige, and (ii) do not only value accuracy but also reward originality—allowing them to alleviate herding effects. We find that under some conditions (large enough success rate of informed agents and intermediate taste for popularity), both social learning’s higher accuracy and the taste for original opinions are evolutionarily-stable, within a mutually beneficial division of labour-like equilibrium. When such conditions are not met, the system most often converges towards mutually detrimental equilibria.

scholarly journals Honeybee Queen mandibular pheromone induces starvation in Drosophila melanogaster, implying a role for nutrition signalling in the evolution of eusociality.

2021 ◽  
Author(s):  
Mackenzie R Lovegrove ◽  
Elizabeth J Duncan ◽  
Peter K Dearden
Keyword(s):  
Drosophila Melanogaster ◽  
Division Of Labour ◽  
Starvation Response ◽  
Queen Mandibular Pheromone ◽  
Honeybee Queen ◽  
Insect Societies ◽  
Reproductive Division Of Labour ◽  
Evolution Of Eusociality ◽  
Reproductive Division ◽  
Behavioural Dominance

Eusocial insect societies are defined by the reproductive division of labour, a social structure that is generally enforced by the reproductive dominant or queen. Reproductive dominance is maintained through behavioural dominance in some species as well as production of queen pheromones in others, or a mixture of both. Queen mandibular pheromone (QMP) is produced by honeybee (Apis mellifera) queens and has been characterised chemically. How QMP acts to repress worker reproduction, and how it has evolved this activity, remains less well understood. Surprisingly, QMP is capable of repressing reproduction in non-target arthropods which have not co-evolved with QMP, are never exposed to QMP in nature, and are up to 530 million years diverged from the honeybee. Here we show that, in Drosophila melanogaster, QMP treatment mimics nutrient limiting conditions, leading to disrupted reproduction. Exposure to QMP induces an increase in food consumption, consistent with that observed in D. melanogaster in response to starvation conditions. This response induces the activation of two checkpoints within the ovary that inhibit oogenesis. The first is the 2a/b ovarian checkpoint in the germarium, which reduces the flow of presumptive oocytes. A stage 9 ovarian checkpoint is also activated, causing degradation of oocytes. The magnitude of activation of both checkpoints is indistinguishable between QMP treated and starved individuals. As QMP seems to trigger a starvation response in an insect highly diverged from honeybees, we propose that QMP originally evolved by co-opting nutrition signalling pathways to regulate reproduction, a key step in the evolution of eusociality.

scholarly journals Morphological evolution in the ant reproductive caste

2020 ◽  
Author(s):  
Raquel Divieso ◽  
Thiago S. R. Silva ◽  
Marcio R. Pie
Keyword(s):  
Body Size ◽  
Morphological Variation ◽  
Morphological Evolution ◽  
Division Of Labour ◽  
Comprehensive Treatment ◽  
Size Distributions ◽  
Reproductive Division Of Labour ◽  
Evolution Of Eusociality ◽  
Worker Caste ◽  
Reproductive Division

AbstractThe evolution of eusociality led to severe changes in the general hymenopteran body plan. In particular, the evolution of reproductive division of labour caused the worker caste to be largely freed from the demands involved in reproduction. As a consequence, workers were able to evolve highly specialized morphologies for foraging and colony maintenance, whereas the reproductive caste became specialized for reproduction. Despite these important changes, little is known about general patterns of morphological evolution within the ant reproductive caste. Our goals were to characterize morphological variation in the ant reproductive caste and to test whether different sexes display variation in their evolutionary rates. We obtained measurements of 897 specimens from a total of 678 ant species. The shapes of the size distributions were similar between sexes, with queens being larger than males in all traits except for eye length. Contrary to the expectation based on Rensch’s rule, although queens were larger, the degree of dimorphism increased with body size. Finally, there is strong evidence for an accelerated tempo of morphological evolution in queens in relation to males. These results represent the first comprehensive treatment of morphological variation in the ant reproductive caste and provide important new insights into their evolution.

scholarly journals Reproductive workers show queen-like gene expression in an intermediately eusocial insect, the buff-tailed bumble beeBombus terrestris.

2014 ◽  
Author(s):  
Mark C Harrison ◽  
Robert L Hammond ◽  
Eamonn B Mallon
Keyword(s):  
Differential Expression ◽  
Bombus Terrestris ◽  
Expression Patterns ◽  
Differential Expression Analysis ◽  
Division Of Labour ◽  
Differentially Expressed ◽  
Bumble Bee ◽  
Strong Shift ◽  
Single Genome ◽  
Eusocial Species

Bumble bees represent a taxon with an intermediate level of eusociality within Hymenoptera. The clear division of reproduction between a single founding queen and the largely sterile workers is characteristic for highly eusocial species, whereas the morphological similarity between the bumble bee queen and the workers is typical for more primitively eusocial hymenopterans. Also, unlike other highly eusocial hymenopterans, division of labour among worker sub-castes is plastic and not predetermined by morphology or age. We conducted a differential expression analysis based on RNA-seq data from 11 combinations of developmental stage and caste to investigate how a single genome can produce the distinct castes of queens, workers and males in the buff-tailed bumble beeBombus terrestris. Based on expression patterns, we found males to be the most distinct of all adult castes (2,411 transcripts differentially expressed compared to non-reproductive workers). However, only relatively few transcripts were differentially expressed between males and workers during development (larvae: 71, pupae: 162). This indicates the need for more distinct expression patterns to control behaviour and physiology in adults compared to those required to create different morphologies. Among female castes, reproductive workers and their non-reproductive sisters displayed differential expression in over ten times more transcripts compared to the differential expression found between reproductive workers and their mother queen. This suggests a strong shift towards a more queen-like behaviour and physiology when a worker becomes fertile. This contrasts with eusocial species where reproductive workers are more similar to non-reproductive workers than the queen.

scholarly journals Macronutrient intakes and the lifespan-fecundity trade-off: a geometric framework agent-based model

2019 ◽  
Vol 16 (151) ◽  
pp. 20180733 ◽  
Author(s):  
Cameron J. Hosking ◽  
David Raubenheimer ◽  
Michael A. Charleston ◽  
Stephen J. Simpson ◽  
Alistair M. Senior
Keyword(s):  
Life History ◽  
Ecological Factors ◽  
Primary Component ◽  
Agent Based Model ◽  
Geometric Framework ◽  
Trade Off ◽  
Agent Based ◽  
Extrinsic Mortality ◽  
Trade Offs ◽  
Evolutionary Fitness

Lifespan and fecundity, the main components in evolutionary fitness, are both strongly affected by nutritional state. Geometric framework of nutrition (GFN) experiments has shown that lifespan and fecundity are separated in nutrient space leading to a functional trade-off between the two traits. Here we develop a spatially explicit agent-based model (ABM) using the GFN to explore how ecological factors may cause selection on macronutrient appetites to optimally balance these life-history traits. We show that increasing the risk of extrinsic mortality favours intake of a mixture of nutrients that is associated with maximal fecundity at the expense of reduced longevity and that this result is robust across spatial and nutritional environments. These model behaviours are consistent with what has been observed in studies that quantify changes in life history in response to environmental manipulations. Previous GFN-derived ABMs have treated fitness as a single value. This is the first such model to instead decompose fitness into its primary component traits, longevity and fecundity, allowing evolutionary fitness to be an emergent property of the two. Our model demonstrates that selection on macronutrient appetites may affect life-history trade-offs and makes predictions that can be directly tested in artificial selection experiments.

scholarly journals Morphological evolution in the ant reproductive caste

2020 ◽  
Vol 131 (3) ◽  
pp. 465-475
Author(s):  
Raquel Divieso ◽  
Thiago S R Silva ◽  
Marcio R Pie
Keyword(s):  
Body Size ◽  
Morphological Variation ◽  
Morphological Evolution ◽  
Division Of Labour ◽  
Comprehensive Treatment ◽  
Size Distributions ◽  
Reproductive Division Of Labour ◽  
Evolution Of Eusociality ◽  
Worker Caste ◽  
Reproductive Division

Abstract The evolution of eusociality has led to considerable changes in the general hymenopteran body plan. In particular, the evolution of reproductive division of labour caused the worker caste to be largely freed from the demands involved in reproduction. As a consequence, workers were able to evolve highly specialized morphologies for foraging and colony maintenance, whereas the reproductive caste became specialized for reproduction. Despite these important changes, little is known about the general patterns of morphological evolution within the ant reproductive caste. Our goals here were to characterize morphological variation in the ant reproductive caste and to test whether different sexes display variation in their evolutionary rates. We obtained measurements of 897 specimens from a total of 678 ant species. The shapes of the size distributions were similar between sexes, with queens being larger than males in all traits except for eye length. Contrary to the expectation based on Rensch’s rule, although queens were larger, the degree of dimorphism increased with body size. Finally, there was strong evidence for an accelerated tempo of morphological evolution in queens in relation to males. These results represent the first comprehensive treatment of morphological variation in the ant reproductive caste and provide important new insights into their evolution.

scholarly journals Family-based guilds in the ant Pachycondyla inversa

2013 ◽  
Vol 9 (3) ◽  
pp. 20130125 ◽  
Author(s):  
Heikki Helanterä ◽  
Oliver Aehle ◽  
Maurice Roux ◽  
Jürgen Heinze ◽  
Patrizia d'Ettorre
Keyword(s):  
Genetic Diversity ◽  
Disease Resistance ◽  
Group Living ◽  
Division Of Labour ◽  
Caste Differentiation ◽  
Evolution Of Sociality ◽  
Ponerine Ant ◽  
Chemical Profiles ◽  
Family Based ◽  
Eusocial Species

High relatedness promotes the evolution of sociality because potentially costly cooperative behaviours are directed towards kin. However, societies, such as those of social insects, also benefit from genetic diversity, e.g. through enhanced disease resistance and division of labour. Effects of genetic diversity have been investigated in a few complex eusocial species. Here, we show that genetically based division of labour may also be important in ‘simple societies’, with fewer individuals and limited morphological caste differentiation. The ponerine ant Pachycondyla inversa has small colonies, headed by several unrelated queens. We show that nest-mate workers from different matrilines engage in different tasks, have distinct chemical profiles and associate preferentially with kin in the nest, while queens and brood stay together. This suggests that genetically based division of labour may precede the evolution of complex eusociality and facilitate the existence of low relatedness societies functioning as associations of distinct families that mutually benefit from group living.

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