In 4, Okayama University's phenomenon was that a male insect called the red flour beetle (Coleoptera: Tenebrionidae) continued to escape without fighting even if it met another male for four days after losing the battle with another male. It was discovered in the laboratory of Professor Takahisa Miyatake.This time, the research group analyzed this phenomenon with a mathematical model.We found that by continuing to run away, we could leave more offspring than others.
The method used this time is a simulation called "individual base model".A mathematical model that simulates how each individual changes by defining the state, behavior, interaction, etc. of each individual as an algorithm, and analyzes from the viewpoint of the evolution of animal behavior patterns. rice field.The focus of consideration is whether the behavior of continuing to escape for four days can leave more offspring (for example, not escaping, escaping for one day, escaping for two days, etc.) than other behaviors (whether it is advantageous).If advantageous, after a long period of time, the population will be occupied by individuals who "escape for four days."
In the research, we consider the state such as whether there is a memory of losing, how many days ago if there is a loss, and the accumulation of damage due to the struggle so far.A simulation similar to a role-playing game was performed in which 201 insects were virtually set in the computer, randomly selected individuals were made to fight, and the losing individual continued to escape for a certain period of time.As a result, it was found that the behavior of continuing to escape for 60 days under the condition that males meet each other 100 to 4 times a day in the group is more advantageous than others.
Animal behavior is believed to have been acquired as a result of evolution.It is expected that this research method will be applied to various studies on evolutionary dynamics.