Peter D. Turney
Volume 26 | Issue 3 | Summer 2020
We present a computational simulation of evolving entities that includes symbiosis with shifting levels of selection. Evolution by natural selection shifts from the level of the original entities to the level of the new symbiotic entity. In the simulation, the fitness of an entity is measured by a series of one-on-one competitions in the Immigration Game, a two-player variation of Conway’s Game of Life. Mutation, reproduction, and symbiosis are implemented as operations that are external to the Immigration Game. Because these operations are external to the game, we can freely manipulate the operations and observe the effects of the manipulations. The simulation is composed of four layers, each layer building on the previous layer. The first layer implements a simple form of asexual reproduction, the second layer introduces a more sophisticated form of asexual reproduction, the third layer adds sexual reproduction, and the fourth layer adds symbiosis. The experiments show that a small amount of symbiosis, added to the other layers, significantly increases the fitness of the population. We suggest that the model may provide new insights into symbiosis in biological and cultural evolution.
An up-to-date overview of the field of connectomics, introducing concepts and mechanisms underlying brain network change at different stages.
The human brain undergoes massive changes during its development, from early childhood and the teenage years to adulthood and old age. Across a wide range of species, from C. elegans and fruit flies to mice, monkeys, and humans, information about brain connectivity (connectomes) at different stages is now becoming available. New approaches in network neuroscience can be used to analyze the topological, spatial, and dynamical organization of such connectomes. In Changing Connectomes, Marcus Kaiser provides an up-to-date overview of the field of connectomics and introduces concepts and mechanisms underlying brain network changes during evolution and development.
Drawing on a range of results from experimental, clinical, and computational studies, Kaiser describes changes during healthy brain maturation and during brain network disorders (including such neurodevelopmental conditions as schizophrenia and depression), brain injury, and neurodegenerative disorders including dementia. He argues that brain stimulation is an area where understanding connectome development could help in assessing long-term effects of interventions. Changing Connectomes is a suitable starting point for researchers who are new to the field of connectomics, and also for researchers who are interested in the link between brain network organization and brain and cognitive development in health and disease. Matlab/Octave code examples available at the MIT Press website will allow computational neuroscience researchers to understand and extend the shown mechanisms of connectome development.
It is our pleasure to welcome you to the inaugural issue of the International Journal of Complexity in Education (IJCE). The aim of the journal is to disseminate mainly empirical research about the application of complexity theory paradigm to educational processes in the broadest sense of the word. The new paradigm focuses on general and specific properties of complex systems and includes the related subfields, such as chaos theory, agent-based modeling, social network analysis, cellular automata and catastrophe theory. In addition, it embraces all other theories and methods that have been developed explicitly to capture complex and unpredictable processes. The above comprise a distinct intellectual tradition that focuses on the study of all things complex, systemic, dynamical and nonlinear and while they typically utilize quantitative approaches, qualitative inquiries are not excluded as long as they adhere to philosophical –ontological and epistemological-considerations of Complex Adaptive Systems (…)
Renormalization has become perhaps the single most important advance in theoretical physics in 50 years.
A novel form of immunological memory that was mostly ignored for a century extends the benefits of vaccines. It could be of help in ending the COVID-19 pandemic.