アリの採餌行動スイッチング模型における経路選択相転移現象�Switching Particle Systems for Foraging Ants and Phase Transitions in Path Selection

4 September 2023, 数理生物学会年会, 奈良女子大学

江添綾七¹, 森本早織¹, 田中雄也¹, 香取眞理¹, 西森拓²

¹中央大学大学院理工学研究科物理学専攻, ²明治大学大学院先端数理科学研究科

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Outline

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Introduction 1:�Switching of Cues by Foraging Ants

• Collective behavior and swarm intelligence of ants have been extensively studied.

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• Ants reach food by following pheromones dropped by other ants.

Edward O. Wilson and Bert Holldobler : `The Ants’, Belknap Press (1990), pp.265-279

https://mas.kke.co.jp/

Introduction 1:�Switching of Cues by Foraging Ants

• Nishimori’s group experiments

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• Ants also perform visual-cues-mediated-walk while foraging.

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• Ants switch between pheromone-mediated-walk and visual-cues-mediated-walk.

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• Whether optimal path is formed or not depends on the turning angle.

Ogihara, Yamanaka, Akino, Izumi, Awazu, Nishimori : in `Mathematical Approaches to Biological Systems’, Springer (2015), pp.119-137

Introduction 2: Switching Interacting Particle Systems and Dormancy Problems

• Two-layer model (switching interacting particle systems)

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Floreani, Giardina, den Hollander, Nandan, Redig : J. Stat. Phys. 186 (2022) 33 (pp.45)

fast particles

Introduction 2: Switching Interacting Particle Systems and Dormancy Problems

• What is dormancy?

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Lennon, den Hollander, Wilke-Berenguer, Blath : Principles of seed banks and the emergence of complexity from dormancy, Nat Commun 12, 4807 (2021) (pp.16)

• Many organisms go dormant in suboptimal environments.

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• Dormant individuals enable same species to survive in sudden environmental changes.

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• Seed bank is a group of dormant individuals.

Stochastic Models for Foraging Path Selection by Ants

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situation-dependent switching

Stochastic Models for Foraging Path Selection by Ants

• pheromone-mediated-walk

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• Ants go forward or turn left or turn right.

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• The probability of choosing forward, left, or right turn depends on amount of pheromone placed at each site.

Stochastic Models for Foraging Path Selection by Ants

• visual-cues-mediated-walk

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• Proceed in a randomly chosen direction toward the nest (left or down).

nest

Stochastic Models for Foraging Path Selection by Ants

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Extreme　Cases

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Extreme　Cases

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Stochastic Models for Foraging Path Selection by Ants

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• We think that the global switching of path selection can be considered as a continuous phase transition.

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• In order to justify this conjecture, we have to study dependence of the results on the system size L.

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Thank you very much for your attention!