scholarly journals Division of labor in work shifts by leaf-cutting ants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pedro B. Constantino ◽  
Veronica S. Valentinuzzi ◽  
André F. Helene
Keyword(s):  
Division Of Labor ◽  
Social System ◽  
Thermal Tolerance ◽  
Time Preference ◽  
Food Sources ◽  
Eusocial Insects ◽  
Leaf Cutting ◽  
Work Shifts ◽  
Worker Activity ◽  
Foraging Time

AbstractForaging rhythms in eusocial insects are determined by the colony´s overall pattern. However, in leaf-cutting ant workers, individual rhythms are not fully synchronized with the colonies’ rhythm. The colony as a whole is nocturnal, since most worker activity takes place at night; however some workers forage during the day. Previous studies in individualized ants suggest nocturnal and diurnal workers coexistence. Here observations within the colony, in leaf-cutting ants, showed that workers have differential foraging time preference, which interestingly is associated to body size and differential leaf transportation engagement. Nocturnal ants are smaller and less engaged in leaf transportation whereas diurnal ants are bigger and more engaged in leaf carriage. Mechanisms underlying division of labor in work shifts in ants are still unknown but much can be extrapolated from honeybees; another social system bearing a similar pattern. A collective organization like this favors constant exploitation of food sources while preserving natural individual rhythm patterns, which arise from individual differences, and thermal tolerance, given by the size polymorphism presented by this species.

scholarly journals Morphological and genomic shifts in mole-rat ‘queens’ increase fecundity but reduce skeletal integrity

2020 ◽  
Author(s):  
Rachel A. Johnston ◽  
Philippe Vullioud ◽  
Jack Thorley ◽  
Henry Kirveslahti ◽  
Leyao Shen ◽  
...  
Keyword(s):  
Division Of Labor ◽  
Morphological Plasticity ◽  
Skeletal Morphology ◽  
Eusocial Insects ◽  
Mole Rat ◽  
Gene Regulatory ◽  
Reproductive Division Of Labor ◽  
Reproductive Division ◽  
Skeletal Integrity ◽  
Vertebral Growth

AbstractIn some mammals and many social insects, highly cooperative societies are characterized by reproductive division of labor, in which breeders and nonbreeders become behaviorally and morphologically distinct. While differences in behavior and growth between breeders and nonbreeders have been extensively described, little is known of their molecular underpinnings. Here, we investigate the consequences of breeding for skeletal morphology and gene regulation in highly cooperative Damaraland mole-rats. By experimentally assigning breeding ‘queen’ status versus nonbreeder status to age-matched littermates, we confirm that queens experience vertebral growth that likely confers advantages to fecundity. However, they also up-regulate bone resorption pathways and show reductions in femoral mass, which predicts increased vulnerability to fracture. Together, our results show that, as in eusocial insects, reproductive division of labor in mole-rats leads to gene regulatory rewiring and extensive morphological plasticity. However, in mole-rats, concentrated reproduction is also accompanied by costs to bone strength.

scholarly journals Morphological and genomic shifts in mole-rat 'queens' increase fecundity but reduce skeletal integrity

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Rachel A Johnston ◽  
Philippe Vullioud ◽  
Jack Thorley ◽  
Henry Kirveslahti ◽  
Leyao Shen ◽  
...  
Keyword(s):  
Division Of Labor ◽  
Morphological Plasticity ◽  
Skeletal Morphology ◽  
Eusocial Insects ◽  
Mole Rat ◽  
Gene Regulatory ◽  
Reproductive Division Of Labor ◽  
Reproductive Division ◽  
Skeletal Integrity ◽  
Vertebral Growth

In some mammals and many social insects, highly cooperative societies are characterized by reproductive division of labor, in which breeders and nonbreeders become behaviorally and morphologically distinct. While differences in behavior and growth between breeders and nonbreeders have been extensively described, little is known of their molecular underpinnings. Here, we investigate the consequences of breeding for skeletal morphology and gene regulation in highly cooperative Damaraland mole-rats. By experimentally assigning breeding 'queen' status versus nonbreeder status to age-matched littermates, we confirm that queens experience vertebral growth that likely confers advantages to fecundity. However, they also up-regulate bone resorption pathways and show reductions in femoral mass, which predicts increased vulnerability to fracture. Together, our results show that, as in eusocial insects, reproductive division of labor in mole-rats leads to gene regulatory rewiring and extensive morphological plasticity. However, in mole-rats, concentrated reproduction is also accompanied by costs to bone strength.

Eusocial Insects as a Model for Understanding Altruism, Cooperation, and Levels of Selection

2020 ◽  
Author(s):  
Heikki Helanterä
Keyword(s):  
Natural Selection ◽  
Division Of Labor ◽  
Social Insect ◽  
Social Evolution ◽  
Inclusive Fitness ◽  
Family Structures ◽  
Major Transitions ◽  
Eusocial Insects ◽  
Insect Societies ◽  
Evolutionary Success

If the logic of natural selection is applied strictly at the level of individual production of offspring, sterile workers in insect societies are enigmatic. How can natural selection ever produce individuals that refrain from reproduction, and how are traits of such individuals that never produce offspring scrutinized and changed through natural selection? The solution to both questions is found in the family structures of insect societies. That is, the sterile helper individuals are evolutionary altruists that give up their own reproduction and instead are helping their kin reproduce and proliferate shared genes in the offspring of the fertile queen. Selection in such cases is not just a matter of individual’s direct reproduction, and instead of own offspring, the currency of the evolutionary success of sterile individuals is inclusive fitness. The concept of inclusive fitness and the process of kin selection are key to understanding the magnificent cooperation we see in insect societies, and reciprocally, insect societies are key case studies of inclusive fitness logic. In extreme cases, such as the highly advanced and sophisticated societies of ants, honeybees, and termites, the division of labor and interdependence of colony members is so complete, that it is justified to talk about a new level of evolutionary individuality. Such increases in the hierarchical complexity of life are called major transitions in evolution. We see adaptations of the colony, rather than individuals, in, e.g., their communication and group behaviors. The division of labor between morphologically differentiated queens and workers is analogous to germline-soma separation of a multicellular organism, justifying the term superorganism for the extreme cases of social lifestyle. Alongside these extreme cases, there is enormous diversity in the social lifestyles across social insect taxa, which provides a window into the balance of cooperation and conflict, and individual reproduction and helping others, in social evolution. Over the last decades, social insect research has been an area where the theoretical and empirical understanding have been developed hand in hand, together with examples of wonderful natural history, and has tremendously improved our understanding of evolution.

scholarly journals Temporal division of labor in an aphid social system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Harunobu Shibao ◽  
Mayako Kutsukake ◽  
Takema Fukatsu
Keyword(s):  
Division Of Labor ◽  
Task Switching ◽  
Age Estimation ◽  
Social System ◽  
Artificial Diet ◽  
Behavioral Observation ◽  
Age Polyethism ◽  
First Instar ◽  
Age Dependent ◽  
And Task

AbstractTemporal division of labor, or age polyethism, in which altruistic caste individuals change their tasks with aging, is widely found in bees and ants (Hymenoptera) and also in other social insects. Here we report the discovery of elaborate age polyethism in a social aphid (Hemiptera). Tuberaphis styraci is a gall-forming aphid in which monomorphic first instar nymphs differentiate into normal nymphs and soldiers upon second instar molt. Soldiers neither grow nor reproduce but perform gall cleaning and colony defense. Using an artificial diet rearing system, we collected age-defined groups of soldiers and monitored their social behaviors. We observed that young soldiers tend to clean whereas old soldiers preferentially attack, thereby verifying age-dependent task switching from housekeeping to defense. Strategic sampling, age estimation and behavioral observation of soldiers from natural galls revealed that (1) young cleaning soldiers tend to inhabit upper gall regions with adult insects, (2) old attacking soldiers tend to be distributed in lower gall regions, particularly around the gall openings, and (3) the gall structure is linked to intra-nest movement, aging and task switching of soldiers in an adaptive manner. These results highlight an evolutionary parallelism comparable to the sophisticated temporal division of labor observed in honeybee colonies.

scholarly journals Mutational meltdown of microbial altruists in Streptomyces coelicolor colonies

2020 ◽  
Author(s):  
Zheren Zhang ◽  
Bart Claushuis ◽  
Dennis Claessen ◽  
Daniel E. Rozen
Keyword(s):  
Division Of Labor ◽  
Streptomyces Coelicolor ◽  
Fold Increase ◽  
Base Substitution ◽  
Natural Mode ◽  
Genomic Deletions ◽  
Eusocial Insects ◽  
Individual Fitness ◽  
Mutant Cells ◽  
Mutational Meltdown

AbstractIn colonies of the filamentous multicellular bacterium Streptomyces coelicolor, a sub-population of cells arise that hyper-produce metabolically costly antibiotics, resulting in a division of labor that maximizes colony fitness. Because these cells contain large genomic deletions that cause massive reductions to individual fitness, their behavior is altruistic, much like worker castes in eusocial insects. To understand the reproductive and genomic fate of these mutant cells after their emergence, we use experimental evolution by serially transferring populations via spore-to-spore transfer for 25 cycles, reflective of the natural mode of bottlenecked transmission for these spore-forming bacteria. We show that, in contrast to wild-type cells, altruistic mutant cells continue to significantly decline in fitness during transfer while they delete larger and larger fragments from their chromosome ends. In addition, altruistic mutants acquire a roughly 10-fold increase in their base-substitution rates due to mutations in genes for DNA replication and repair. Ecological damage, caused by reduced sporulation, coupled with irreversible DNA damage due to point mutation and deletions, leads to an inevitable and irreversible type of mutational meltdown in these cells. Taken together, these results suggest that the altruistic cells arising in this division of labor are equivalent to reproductively sterile castes of social insects.

scholarly journals Integrative Responses of Leaf-Cutting Ants to Temperature Rises

2020 ◽  
Author(s):  
Cleverson de Sousa Lima ◽  
André Frazão Helene ◽  
Agustín Camacho
Keyword(s):  
Body Size ◽  
Relative Humidity ◽  
Thermal Tolerance ◽  
Heating Rates ◽  
Atta Sexdens ◽  
Physiological Tolerance ◽  
Labor Division ◽  
Leaf Cutting ◽  
Summary Statement ◽  
Start Temperature

AbstractThermal variation has complex effects on organisms and they deal with it by combining behavioral and physiological thermal tolerance. However, we still do not understand well how these two types of traits relate to body condition (e.g. size, hydration) and environmental variables (e.g. relative humidity), some of which are typical aspects of thermal tolerance experiments (warming rates, start temperature). We explored these interactions using a set of experiments that sequentially measure behavioral (Voluntary Thermal Maxima) and physiological thermal tolerance (Critical Thermal Maxima) for individuals of Atta sexdens rubropilosa (Forel, 1908). We found non-linear effects of body size on behavioral thermal tolerance and refuted the traditional hypothesis that body size increases ant’s physiological thermal tolerance. Hydration state and humidity had complex effects on behavioral and physiological tolerance. However, both tolerance measures increased with heating rates and start temperature. Our work helps understanding how an ectotherm integrates stimuli affecting its thermal tolerance to decide which temperatures to avoid. We discuss implications for the ecology of ants, their labor division, and for their susceptibility to climate warming and drought.Summary StatementHere we show how internal (body size, hydration level) and external factors (heating rate, relative humidity) affect leaf-cutting ants behavioral and physiological responses to temperature rises.

scholarly journals How Gradient Affects the Foraging Decisions of Leaf Cutting Ants at the Food Source

2019 ◽  
Author(s):  
◽  
Sam Butler
Keyword(s):  
Foraging Behaviour ◽  
Feeding Site ◽  
Individual Level ◽  
Eusocial Insects ◽  
Methodological Errors ◽  
Foraging Decisions ◽  
Key Factor ◽  
Leaf Cutting ◽  
Load Size ◽  
Insight Into

The eusocial insects have long held the fascination of scientists for their co-operative behaviour, which can range from a small group of workers, to millions strong colonies, such as those found in the leaf cutting ant, Atta cephalotes. Though decades of research have allowed us some insight into their organisation and methods, there are many things that have gone unexplained. One of these is the mystery of why Atta consistently takes leaf loads back to the nest that are significantly smaller than would be optimal, when they should in theory optimise leaf transport rate. While compelling evidence has been presented to suggest that it is at least in part to do with how the leaves are processed inside the nest, here I present evidence to suggest that gradient is another key factor. This is a factor which has been explored only very cursorily up until now in leaf cutting ants, with experiments investigating it being extremely limited in scope, suffer from potential methodological errors or deal with grass cutting ants, which share many traits with leaf cutting ants, but have adapted to face different challenges. Upon a thorough examination of the effects of gradient, it was discovered that A. cephalotes favour a cautious, but more reliable method of transport. At almost every point, their behaviour shows the importance of maintaining grip on steep and vertical gradients to the point where it is prioritised over everything else, including speed and load size. While it may seem paradoxical to suggest that smaller loads, carried slower might result in a higher overall rate of leaf collection, a fast, but reckless approach might result in a high proportion of unsuccessful foraging trips, each of which costs energy and time. As a result, by increasing their success, rather than speed, they minimise wasted effort, loss of workers and potentially, have a higher rate of leaf collection over time. This aspect of leaf cutting ant behaviour shows that leaf cutting ants can change their priorities at the feeding site to best maximise transport success at an individual level, which demonstrates previously unappreciated plasticity and a new lens through which to view future investigations into ant foraging behaviour.

scholarly journals Division of labor increases with colony size, regardless of group composition, in the social spiderStegodyphus dumicola

2019 ◽  
Author(s):  
Colin M. Wright ◽  
James L. L. Lichtenstein ◽  
C. Tate Holbrook ◽  
Justin Pretorius ◽  
Noa Pinter-Wollman ◽  
...  
Keyword(s):  
Division Of Labor ◽  
Group Size ◽  
Colony Size ◽  
Prey Capture ◽  
Work Organization ◽  
Group Function ◽  
Social Spiders ◽  
Eusocial Insects ◽  
Save Energy ◽  
Web Construction

AbstractDivision of labor (DOL) is a pattern of work organization where individual group members specialize on different tasks. DOL is argued to have been instrumental for the success of eusocial insects, where it scales positively with group size both within and across species. Here we evaluate whether DOL scales positively with group size in a society of cooperative breeders (social spiders) and whether this pattern is impacted by the behavioral composition of the group. To do this we engineered experimental colonies of contrasting group sizes and behavioral compositions and tracked individuals participation in two colony maintenance tasks: prey capture and web construction. As with some eusocial insects, we found that larger groups exhibited DOL metrics up to 10-times greater than smaller groups, conveying that individuals specialize on particular tasks more in larger colonies. This scalar relationship did not differ by a groups behavioral composition, though groups composed of only bold spiders exhibited reduced DOL relative to all-shy or mixed groups. We also found that per capita participation in prey capture, but not web construction, decreased as a function of group size. This suggests that individuals in larger groups may save energy by reducing their involvement in some tasks. Together, our results convey that similar scalar relationships between DOL and group size can emerge both inside and outside the eusocial insects. Thus, theory developed for understanding DOL in eusocial societies may inform our understanding of group function in a larger swath of animal social diversity than is broadly appreciated.SignificanceStatementDivision of labor (DOL) has been a major area of research in the eusocial insects for decades, and is argues to underlie their ecological success. Only recently have other social arthropods, such as social spiders, been considered for studies concerning DOL. Given their smaller colony sizes, and absence of morphological castes, DOL was not thought to be an important facet of spider societies. However, we found that spider societies do indeed exhibit high degrees of DOL that is positively correlated to colony size, as seen in many eusocial insects. These findings suggest that the scalar relationship between group size and social organization seen in social insects is likely generalizable to a larger diversity of social taxa, and that cooperative breeders can show levels of division of labor equaling or exceeding those of eusocial systems evaluated to date.

KRITIK EKONOMI ISLAM TERHADAP PEMIKIRAN KARL MARX TENTANG SISTEM KEPEMILIKAN DALAM SISTEM SOSIAL MASYARAKAT

2017 ◽  
Vol 1 (2) ◽  
pp. 171-187
Author(s):  
Muhammad Kambali
Keyword(s):  
Division Of Labor ◽  
Distribution System ◽  
Social System ◽  
Karl Marx ◽  
System Development ◽  
Historical Materialism ◽  
Capitalist System ◽  
Stage Of Development ◽  
The Social

The theory of Karl Marx’s Historical Materialism states that system of ownership is a necessity in the social system. Marx declares the social system development takes place in five stages. The first stage is primitive-communal society has have not recognized the system of ownership. The second stage is the stage of division of labor and the emergence of ownership. The third stage is formation of feudal society. The fourth stage is development of a capitalist community. The final stage is stage of development of the social system which is the formation of a socialist-communist society. If seen from ownership, the social-communal system is divided into three sections; the stage of primitive-communal society, the division of labor and the stages of ownership, and phase of the ownership elimination. According to Marx, the ownership of proletariat workers system suffers exploitation and alienation. Both of these things can only be solved by removing the ownership system which is replaced by the role of collective ownership. For Islamic economics, exploitation and alienation experienced by the proletariat workers are the result of inconsistencies in wealth management and distribution system in the capitalist system, not proprietary. Islamic Economics is looking at the role of individuals in managing their wealth and their distribution pattern.

scholarly journals Mortality rates and division of labor in the leaf-cutting ant, Atta colombica

2006 ◽  
Vol 6 (18) ◽  
pp. 1-8 ◽  
Author(s):  
Mark J F. Brown ◽  
A N M. Bot ◽  
Adam G. Hart
Keyword(s):  
Division Of Labor ◽  
Mortality Rates ◽  
Leaf Cutting ◽  
Atta Colombica
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