Month: November 2023

How Turing parasites expand the computational landscape of digital life

Luís F. Seoane and Ricard Solé

Phys. Rev. E 108, 044407

Why are living systems complex? Why does the biosphere contain living beings with complexity features beyond those of the simplest replicators? What kind of evolutionary pressures result in more complex life forms? These are key questions that pervade the problem of how complexity arises in evolution. One particular way of tackling this is grounded in an algorithmic description of life: living organisms can be seen as systems that extract and process information from their surroundings to reduce uncertainty. Here we take this computational approach using a simple bit string model of coevolving agents and their parasites. While agents try to predict their worlds, parasites do the same with their hosts. The result of this process is that, to escape their parasites, the host agents expand their computational complexity despite the cost of maintaining it. This, in turn, is followed by increasingly complex parasitic counterparts. Such arms races display several qualitative phases, from monotonous to punctuated evolution or even ecological collapse. Our minimal model illustrates the relevance of parasites in providing an active mechanism for expanding living complexity beyond simple replicators, suggesting that parasitic agents are likely to be a major evolutionary driver for biological complexity.

Read the full article at: link.aps.org

Lévy movements and a slowly decaying memory allow efficient collective learning in groups of interacting foragers

Falcón-Cortés A, Boyer D, Aldana M, Ramos-Fernández G (2023) Lévy movements and a slowly decaying memory allow efficient collective learning in groups of interacting foragers. PLoS Comput Biol 19(10): e1011528.

Many animal species benefit from spatial learning to adapt their foraging movements to the distribution of resources. Learning involves the collection, storage and retrieval of information, and depends on both the random search strategies employed and the memory capacities of the individual. For animals living in social groups, spatial learning can be further enhanced by information transfer among group members. However, how individual behavior affects the emergence of collective states of learning is still poorly understood. Here, with the help of a spatially explicit agent-based model where individuals transfer information to their peers, we analyze the effects on the use of resources of varying memory capacities in combination with different exploration strategies, such as ordinary random walks and Lévy flights. We find that individual Lévy displacements associated with a slow memory decay lead to a very rapid collective response, a high group cohesion and to an optimal exploitation of the best resource patches in static but complex environments, even when the interaction rate among individuals is low.

Read the full article at: journals.plos.org

Dynamical Phase Transitions in Graph Cellular Automata

Freya Behrens, Barbora Hudcová, Lenka Zdeborová

Discrete dynamical systems can exhibit complex behaviour from the iterative application of straightforward local rules. A famous example are cellular automata whose global dynamics are notoriously challenging to analyze. To address this, we relax the regular connectivity grid of cellular automata to a random graph, which gives the class of graph cellular automata. Using the dynamical cavity method (DCM) and its backtracking version (BDCM), we show that this relaxation allows us to derive asymptotically exact analytical results on the global dynamics of these systems on sparse random graphs. Concretely, we showcase the results on a specific subclass of graph cellular automata with “conforming non-conformist” update rules, which exhibit dynamics akin to opinion formation. Such rules update a node’s state according to the majority within their own neighbourhood. In cases where the majority leads only by a small margin over the minority, nodes may exhibit non-conformist behaviour. Instead of following the majority, they either maintain their own state, switch it, or follow the minority. For configurations with different initial biases towards one state we identify sharp dynamical phase transitions in terms of the convergence speed and attractor types. From the perspective of opinion dynamics this answers when consensus will emerge and when two opinions coexist almost indefinitely.

Read the full article at: arxiv.org

Quantifying hierarchy and prestige in US ballet academies as social predictors of career success

Yessica Herrera-Guzmán, Alexander J. Gates, Cristian Candia & Albert-László Barabási 
Scientific Reports volume 13, Article number: 18594 (2023)

In the recent decade, we have seen major progress in quantifying the behaviors and the impact of scientists, resulting in a quantitative toolset capable of monitoring and predicting the career patterns of the profession. It is unclear, however, if this toolset applies to other creative domains beyond the sciences. In particular, while performance in the arts has long been difficult to quantify objectively, research suggests that professional networks and prestige of affiliations play a similar role to those observed in science, hence they can reveal patterns underlying successful careers. To test this hypothesis, here we focus on ballet, as it allows us to investigate in a quantitative fashion the interplay of individual performance, institutional prestige, and network effects. We analyze data on competition outcomes from 6363 ballet students affiliated with 1603 schools in the United States, who participated in the Youth America Grand Prix (YAGP) between 2000 and 2021. Through multiple logit models and matching experiments, we provide evidence that schools’ strategic network position bridging between communities captures social prestige and predicts the placement of students into jobs in ballet companies. This work reveals the importance of institutional prestige on career success in ballet and showcases the potential of network science approaches to provide quantitative viewpoints for the professional development of careers beyond science.

Read the full article at: www.nature.com

Phenomenology and Complexity

Andrea Zhok

Foundations of Science 28, pages 1047–1058 (2023)

This text aims to show how some substantial ontological conclusions, consistent with the notion of ‘complexity’, can be demonstrated through elementary phenomenological analyzes. In particular, we will show that it is necessary to acknowledge an ontology where the forms of ontological efficacy cannot be reduced to efficient causality, the relations between properties are irreducible to deduction, irreducible qualities must exist originally, further qualities emerge from existing qualities, and no explanatory key less complex than the fullness of consciousness’ functions can account for reality.

Read the full article at: link.springer.com