scholarly journals Individual-Level and Population-Level Lateralization: Two Sides of the Same Coin

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 739 ◽  
Author(s):  
Elisa Frasnelli ◽  
Giorgio Vallortigara
Keyword(s):  
Evolutionarily Stable Strategy ◽  
Population Level ◽  
Point Of View ◽  
Theoretical Point ◽  
Evolutionarily Stable Strategies ◽  
Functional Roles ◽  
Individual Level ◽  
Social Species ◽  
The Individual ◽  
Evolutionarily Stable

Lateralization, i.e., the different functional roles played by the left and right sides of the brain, is expressed in two main ways: (1) in single individuals, regardless of a common direction (bias) in the population (aka individual-level lateralization); or (2) in single individuals and in the same direction in most of them, so that the population is biased (aka population-level lateralization). Indeed, lateralization often occurs at the population-level, with 60–90% of individuals showing the same direction (right or left) of bias, depending on species and tasks. It is usually maintained that lateralization can increase the brain’s efficiency. However, this may explain individual-level lateralization, but not population-level lateralization, for individual brain efficiency is unrelated to the direction of the asymmetry in other individuals. From a theoretical point of view, a possible explanation for population-level lateralization is that it may reflect an evolutionarily stable strategy (ESS) that can develop when individually asymmetrical organisms are under specific selective pressures to coordinate their behavior with that of other asymmetrical organisms. This prediction has been sometimes misunderstood as it is equated with the idea that population-level lateralization should only be present in social species. However, population-level asymmetries have been observed in aggressive and mating displays in so-called “solitary” insects, suggesting that engagement in specific inter-individual interactions rather than “sociality” per se may promote population-level lateralization. Here, we clarify that the nature of inter-individuals interaction can generate evolutionarily stable strategies of lateralization at the individual- or population-level, depending on ecological contexts, showing that individual-level and population-level lateralization should be considered as two aspects of the same continuum.

forming an asymmetrical brain: genes, environment, and evolutionarily stable strategies

2005 ◽  
Vol 28 (4) ◽  
pp. 615-623 ◽  
Author(s):  
giorgio vallortigara ◽  
lesley j. rogers
Keyword(s):  
Evolutionarily Stable Strategy ◽  
Population Level ◽  
Brain Lateralization ◽  
Evolutionarily Stable Strategies ◽  
Evolutionary Account ◽  
Advantages And Disadvantages ◽  
Alternative Hypotheses ◽  
The Individual ◽  
Present Response ◽  
Evolutionarily Stable

the present response elaborates and defends the main theses advanced in the target article: namely, that in order to provide an evolutionary account of brain lateralization, we should consider advantages and disadvantages associated both with the individual possession of an asymmetrical brain and with the alignment of the direction of lateralization at the population level. we explain why we believe that the hypothesis that directional lateralization evolved as an evolutionarily stable strategy may provide a better account than alternative hypotheses. we also further our discussion of the influence of stimulation and experience in early life on lateralization, and thereby show that our hypothesis is not deterministic. we also consider some novel data and ideas in support of our main thesis.

scholarly journals Scramble in behaviour and ecology

2000 ◽  
Vol 355 (1403) ◽  
pp. 1637-1645 ◽  
Author(s):  
G. A. Parker
Keyword(s):  
Evolutionarily Stable Strategy ◽  
Individual Level ◽  
Patchy Habitat ◽  
Per Capita ◽  
The Difference ◽  
The Individual ◽  
The Relationship ◽  
Resource Input ◽  
Evolutionarily Stable ◽  
Ideal Free

Nicholson's distinction between ‘scramble’ and ‘contest’ modes of competition has received widespread attention in ecology and in behaviour, though the emphasis has been different between the two disciplines. In ecology the focus has been on the effects on population; in behavioural ecology the focus has been on the consequences at the individual level. This paper reviews and develops a theory of scramble competition at the individual level, deriving a general evolutionarily stable strategy (ESS) for individual scramble expenditure in a patchy habitat in which individuals compete in local groups for available resources, and examines two population consequences. The critical parameter determining the relationship between individual scramble expenditure and the number of competitors in a patch is the expected resource per capita. If resource input, R , to a patch is constant and independent of the number of competitors, n , then as the number of competitors increases, the per–capita resources declines as R / n , and the ESS scramble level declines (in proportion to ( n −1)/ n 2 ). However, if the resource input to a patch is positively related to the number of competitors in the patch, scramble expenditure may increase with the number of competitors. In the case where the per–capita resource input stays constant (i.e. R ( n ) = Rn ), the scramble level increases with competitor number (in proportion to ( n −1)/ n ). There are plausible ecological reasons why either of these extreme limits may be approached in nature, making it important to ascertain the relationship between R and n before predicting individual scramble expenditure. For example, resource input may be constant when groups of competitors are constrained to remain together in given patches, and constant per–capita resources may be approached when ideal–free foraging rules apply. However, in the latter case, scramble expenditure must be accounted for in determining the idealfree distribution. An analysis shows that this leads to ‘undermatching’, i.e. the ratio of numbers of competitors for good/bad patches becomes progressively less than the ratio of input rates for good/bad patches as the difference between the good and bad patches increases. A second population consequence of the scramble ESS relates to the fact that scrambles may dramatically affect fitness. The per–capita gain in energy can be reduced by a factor of up to 1/ n as a result of scramble expenditure, potentially reducing realized population size to as little as the square root of the maximum potential carrying capacity, though reasons are given why such large reductions are unlikely.

scholarly journals Exploring the impact of lesser-known social dynamics on wolf populations through an individual-based approach

2020 ◽  
Author(s):  
Sarah Bauduin ◽  
Oksana Grente ◽  
Nina Luisa Santostasi ◽  
Paolo Ciucci ◽  
Christophe Duchamp ◽  
...  
Keyword(s):  
Life Cycle ◽  
Social Dynamics ◽  
Population Level ◽  
Field Investigation ◽  
Adoption Process ◽  
Individual Level ◽  
Social Species ◽  
The Individual ◽  
The Impact ◽  
Management And Conservation

AbstractThe occurrence of wolf populations in human-dominated landscapes is challenging worldwide because of conflicts with human activities. Modeling is an important tool to predict wolf dynamics and expansion, and help in decision making concerning management and conservation. However, some individual behaviors and pack dynamics of the wolf life cycle are still unclear to ecologists. Here we present an individual-based model (IBM) to project wolf populations while exploring the lesser-known processes of the wolf life cycle. IBMs are bottom-up models that simulate the fate of individuals interacting with each other, with population-level properties emerging from the individual-level simulations. IBMs are particularly adapted to represent social species such as the wolf that exhibits complex individual interactions. Our IBM predicts wolf demography including fine-scale individual behavior and pack dynamics based on up-to-date scientific literature. We explore four processes of the wolf life cycle whose consequences on population dynamics are still poorly understood: the pack dissolution following the loss of a breeder, the adoption of young dispersers by packs, the establishment of new packs through budding, and the different types of breeder replacement. While running different versions of the IBM to explore these processes, we also illustrate the modularity and flexibility of our model, an asset to model wolf populations experiencing different ecological and demographic conditions. The different parameterization of pack dissolution, territory establishment by budding, and breeder replacement processes influence the most the projections of wolf populations. As such, these processes require further field investigation to be better understood. The adoption process has a lesser impact on model predictions. Being coded in R to facilitate its understanding, we expect that our model will be used and further adapted by ecologists for their own specific applications.

A dynamic programming approach to evolutionarily stable strategy theory

1980 ◽  
Vol 12 (1) ◽  
pp. 3-5 ◽  
Author(s):  
C. Cannings ◽  
D. Gardiner
Keyword(s):  
Dynamic Programming ◽  
Density Function ◽  
Evolutionarily Stable Strategy ◽  
Programming Approach ◽  
Stable Strategy ◽  
War Of Attrition ◽  
Dynamic Programming Approach ◽  
The Individual ◽  
Image Position ◽  
Evolutionarily Stable

In the war of attrition (wa), introduced by Maynard Smith (1974), two contestants play values from [0, ∞), the individual playing the longer value winning a fixed prize V, and both incurring a loss equal to the lesser of the two values. Thus the payoff, E(x, y) to an animal playing x against one playing y, is A more general form (Bishop and Cannings (1978)) has and it was demonstrated that with and there exists a unique evolutionarily stable strategy (ess), which is to choose a random value from a specified density function on [0, ∞). Results were also obtained for strategy spaces [0, s] and [0, s).

scholarly journals Intraspecific competition and coordination in the evolution of lateralization

2008 ◽  
Vol 364 (1519) ◽  
pp. 861-866 ◽  
Author(s):  
Stefano Ghirlanda ◽  
Elisa Frasnelli ◽  
Giorgio Vallortigara
Keyword(s):  
Evolutionarily Stable Strategy ◽  
Population Level ◽  
Neural Circuitry ◽  
Brain Lateralization ◽  
Stable Strategy ◽  
Cooperative Interactions ◽  
Strategic Factors ◽  
Left And Right ◽  
Predator Interactions ◽  
Evolutionarily Stable

Recent studies have revealed a variety of left–right asymmetries among vertebrates and invertebrates. In many species, left- and right-lateralized individuals coexist, but in unequal numbers (‘population-level’ lateralization). It has been argued that brain lateralization increases individual efficiency (e.g. avoiding unnecessary duplication of neural circuitry and reducing interference between functions), thus counteracting the ecological disadvantages of lateral biases in behaviour (making individual behaviour more predictable to other organisms). However, individual efficiency does not require a definite proportion of left- and right-lateralized individuals. Thus, such arguments do not explain population-level lateralization. We have previously shown that, in the context of prey–predator interactions, population-level lateralization can arise as an evolutionarily stable strategy when individually asymmetrical organisms must coordinate their behaviour with that of other asymmetrical organisms. Here, we extend our model showing that populations consisting of left- and right-lateralized individuals in unequal numbers can be evolutionarily stable, based solely on strategic factors arising from the balance between antagonistic (competitive) and synergistic (cooperative) interactions.

scholarly journals Migration, acculturation, and the maintenance of between-group cultural variation

2017 ◽  
Author(s):  
Alex Mesoudi
Keyword(s):  
Social Learning ◽  
Cultural Values ◽  
Cultural Evolution ◽  
Population Level ◽  
Empirical Literature ◽  
Cultural Variation ◽  
Individual Level ◽  
And Migration ◽  
The Individual ◽  
Social Learning Processes

AbstractHow do migration and acculturation (i.e. psychological or behavioral change resulting from migration) affect within- and between-group cultural variation? Here I answer this question by drawing analogies between genetic and cultural evolution. Population genetic models show that migration rapidly breaks down between-group genetic structure. In cultural evolution, however, migrants or their descendants can acculturate to local behaviors via social learning processes such as conformity, potentially preventing migration from eliminating between-group cultural variation. An analysis of the empirical literature on migration suggests that acculturation is common, with second and subsequent migrant generations shifting, sometimes substantially, towards the cultural values of the adopted society. Yet there is little understanding of the individual-level dynamics that underlie these population-level shifts. To explore this formally, I present models quantifying the effect of migration and acculturation on between-group cultural variation, for both neutral and costly cooperative traits. In the models, between-group cultural variation, measured using F statistics, is eliminated by migration and maintained by conformist acculturation. The extent of acculturation is determined by the strength of conformist bias and the number of demonstrators from whom individuals learn. Acculturation is countered by assortation, the tendency for individuals to preferentially interact with culturally-similar others. Unlike neutral traits, cooperative traits can additionally be maintained by payoff-biased social learning, but only in the presence of strong sanctioning institutions. Overall, the models show that surprisingly little conformist acculturation is required to maintain realistic amounts of between-group cultural diversity. While these models provide insight into the potential dynamics of acculturation and migration in cultural evolution, they also highlight the need for more empirical research into the individual-level learning biases that underlie migrant acculturation.

scholarly journals FEATURES OF BREEDING VALUE INHERITANCE SIRES OF HOLSTEIN BREED

2021 ◽  
Vol 61 ◽  
pp. 64-72
Author(s):  
А. P. Кrugliak ◽  
Т. О. Кrugliak
Keyword(s):  
Milk Yield ◽  
Population Level ◽  
Point Of View ◽  
Breeding Value ◽  
Phenotypic Correlation ◽  
Intermediate Form ◽  
Theoretical Point ◽  
Genetic Progress ◽  
Holstein Breed ◽  
Additive Form

In our studies, the phenotypic manifestation of the additive form of inheritance of breeding value by milk yield (intermediate and parental dominance) was in 334 (82.2%) bulls, and non-additive form (over-dominance and regression) – in 72 (17.8%) including: over-dominance in 55 (13.5%) and regression in 17 heads (4.2%). In the population assessment, for all forms of inheritance, there was a clear quantitative shift of the breeding value of sons of milk yield to positive (+) values, compared with the breeding value of their parents. This confirms that sons, selected after their evaluation, and recognized as milk yield improvers. The variability of the breeding value of sons by milking depending on the forms of its inheritance has been established. According to the group of bulls by intermediate type of inheritance, milk yield sign were found in 291 (71.7%) sons, whose pedigree value was 606.4 ± 11.6 kg and was higher than the half-sum of both parents (554 kg), which deviates from the action of intermediate inheritance at 52 kg (109%). After all, the recognition of the intermediate nature of inheritance involves obtaining in the offspring of animals with the same set of chromosomes as their parents, and hence with the same phenotype. Therefore, from a theoretical point of view, genetic progress in the population should be not expected from this group of animals. However, in this case, the increase in breeding value was 9%, which is statistically significant (P > 0.99). A rather high variability of the breeding value of sons from its level in their parents with an intermediate form of inheritance has been established. Thus, of the 159 bulls-breeders in which the breeding value was inherited by intermediate form, only 30 sons (7.3% of the total population) of the bull Duster 2147488 (BV +579 kg and mothers with an average BV +632 kg, half the amount of the BV of both parents was +605 kg), was +605.5 ± 30.8 kg and was equal to the half-sum of the BV of both parents, and 9 (2.2%) sons of the bull Manfred 2183007, whose breeding value was, on average, at the population level +856.3 ± 37.6 kg and was equal to the half-sum of the indicator of the parents' BV (+851 kg). The inheritance of breeding value of bulls on quantitative signs of milk productivity in highly consolidated breeds on these signs, at intra-breeding selection occurs by a combination of phenotypic display of action of additive and non-additive (super-dominance) forms of inheritance. The frequency of these forms of inheritance probably is determined by the number and quality of chromosome pairs in the karyotype of animals on the probable basis of their manifestation in the population [15]. The relative variability of breeding value by milk yield along the line "father – son" and "mother – son" depends on the form of its inheritance. The coefficient of phenotypic correlation between the breeding value of parents and sons in the intermediate form of inheritance is +0.524 – +0.560 and increases with parental dominance to +0.907 ± 0.040 and +0.985 ± 0.006, and over-dominance to +0.887 ± 0.044 and +0.905 ± 0.033, at high statistical significant. Inheritance by non-additive form (over-dominance of both parents) is more effectively associated with increasing of breeding value by milk yield their sons than by the additive form.

scholarly journals General intelligence disentangled via a generality metric for natural and artificial intelligence

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Hernández-Orallo ◽  
Bao Sheng Loe ◽  
Lucy Cheke ◽  
Fernando Martínez-Plumed ◽  
Seán Ó hÉigeartaigh
Keyword(s):  
Task Difficulty ◽  
Population Level ◽  
Limited Resources ◽  
General Intelligence ◽  
Individual Level ◽  
Cognitive Efficiency ◽  
Comprehensive Performance ◽  
Individual Measure ◽  
Level Of Difficulty ◽  
The Individual

AbstractSuccess in all sorts of situations is the most classical interpretation of general intelligence. Under limited resources, however, the capability of an agent must necessarily be limited too, and generality needs to be understood as comprehensive performance up to a level of difficulty. The degree of generality then refers to the way an agent’s capability is distributed as a function of task difficulty. This dissects the notion of general intelligence into two non-populational measures, generality and capability, which we apply to individuals and groups of humans, other animals and AI systems, on several cognitive and perceptual tests. Our results indicate that generality and capability can decouple at the individual level: very specialised agents can show high capability and vice versa. The metrics also decouple at the population level, and we rarely see diminishing returns in generality for those groups of high capability. We relate the individual measure of generality to traditional notions of general intelligence and cognitive efficiency in humans, collectives, non-human animals and machines. The choice of the difficulty function now plays a prominent role in this new conception of generality, which brings a quantitative tool for shedding light on long-standing questions about the evolution of general intelligence and the evaluation of progress in Artificial General Intelligence.

scholarly journals Ecology and Prediction of Compensatory Growth: From Theory to Application in Forestry

2021 ◽  
Vol 12 ◽  
Author(s):  
Chao Li ◽  
Hugh Barclay ◽  
Bernard Roitberg ◽  
Robert Lalonde
Keyword(s):  
Compensatory Growth ◽  
Population Level ◽  
Human Society ◽  
Common Phenomenon ◽  
Partial Mortality ◽  
Individual Level ◽  
State Dependent ◽  
Dependent Model ◽  
Accelerated Growth ◽  
The Individual

Compensatory growth has been observed in forests, and it also appears as a common phenomenon in biology. Though it sometimes takes different names, the essential meanings are the same, describing the accelerated growth of organisms when recovering from a period of unfavorable conditions such as tissue damage at the individual level and partial mortality at the population level. Diverse patterns of compensatory growth have been reported in the literature, ranging from under-, to compensation-induced-equality, and to over-compensation. In this review and synthesis, we provide examples of analogous compensatory growth from different fields, clarify different meanings of it, summarize its current understanding and modeling efforts, and argue that it is possible to develop a state-dependent model under the conceptual framework of compensatory growth, aimed at explaining and predicting diverse observations according to different disturbances and environmental conditions. When properly applied, compensatory growth can benefit different industries and human society in various forms.

scholarly journals Opposite outcomes of coinfection at individual and population scales

2018 ◽  
Vol 115 (29) ◽  
pp. 7545-7550 ◽  
Author(s):  
Erin E. Gorsich ◽  
Rampal S. Etienne ◽  
Jan Medlock ◽  
Brianna R. Beechler ◽  
Johannie M. Spaan ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Negative Impact ◽  
Scale Up ◽  
Population Level ◽  
Clear Understanding ◽  
African Buffalo ◽  
Global Public Health ◽  
Individual Level ◽  
Secondary Infections ◽  
The Individual

Coinfecting parasites and pathogens remain a leading challenge for global public health due to their consequences for individual-level infection risk and disease progression. However, a clear understanding of the population-level consequences of coinfection is lacking. Here, we constructed a model that includes three individual-level effects of coinfection: mortality, fecundity, and transmission. We used the model to investigate how these individual-level consequences of coinfection scale up to produce population-level infection patterns. To parameterize this model, we conducted a 4-y cohort study in African buffalo to estimate the individual-level effects of coinfection with two bacterial pathogens, bovine tuberculosis (bTB) and brucellosis, across a range of demographic and environmental contexts. At the individual level, our empirical results identified bTB as a risk factor for acquiring brucellosis, but we found no association between brucellosis and the risk of acquiring bTB. Both infections were associated with reductions in survival and neither infection was associated with reductions in fecundity. The model reproduced coinfection patterns in the data and predicted opposite impacts of coinfection at individual and population scales: Whereas bTB facilitated brucellosis infection at the individual level, our model predicted the presence of brucellosis to have a strong negative impact on bTB at the population level. In modeled populations where brucellosis was present, the endemic prevalence and basic reproduction number (R0) of bTB were lower than in populations without brucellosis. Therefore, these results provide a data-driven example of competition between coinfecting pathogens that occurs when one pathogen facilitates secondary infections at the individual level.

Sign in / Sign up

Export Citation Format

Share Document