Evolution of self-organized division of labor in a response threshold model.

Division of labor in social insects is determinant to their ecological success. Recent models emphasize that division of labor is an emergent property of the interactions among nestmates obeying to simple behavioral rules. However, the role of evolution in shaping these rules has been largely neglected. Here, we investigate a model that integrates the perspectives of self-organization and evolution. Our point of departure is the response threshold model, where we allow thresholds to evolve. We ask whether the thresholds will evolve to a state where division of labor emerges in a form that fits the needs of the colony. We find that division of labor can indeed evolve through the evolutionary branching of thresholds, leading to workers that differ in their tendency to take on a given task. However, the conditions under which division of labor evolves depend on the strength of selection on the two fitness components considered: amount of work performed and on worker distribution over tasks. When selection is strongest on the amount of work performed, division of labor evolves if switching tasks is costly. When selection is strongest on worker distribution, division of labor is less likely to evolve. Furthermore, we show that a biased distribution (like 3:1) of workers over tasks is not easily achievable by a threshold mechanism, even under strong selection. Contrary to expectation, multiple matings of colony foundresses impede the evolution of specialization. Overall, our model sheds light on the importance of considering the interaction between specific mechanisms and ecological requirements to better understand the evolutionary scenarios that lead to division of labor in complex systems. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1343-2) contains supplementary material, which is available to authorized users.

Monthly Labor Force Data, December 2013

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, January 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, March 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, April 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, May 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, June 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, August 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Monthly Labor Force Data, September 2014

Monthly Labor Force Data report produced by the Iowa Workforce Development.

Do more educated leaders raise citizens’ education?

This paper looks at the contribution of political leaders to enhance citizens education and investigate how the educational attainment of the population is affected while a leader with higher education remains in office. For this purpose, we consider educational transitions of political leaders in office and find that the educational attainment of population increases when a more educated leader remains in office. Furthermore, we also observe that the educational attainment of the population is negatively impacted when a country transitions from an educated leader to a less educated one. This result may help to explain the previous finding that more educated political leaders favor economic growth. Key Words: Political leaders, Primary Education, School Achievement, Political institutions. JEL classification: I21,I25,I28.