Emergent Periodicity in Fireflies

Overview:

Individual fireflies show no periodicity in their flash pattern emission, drawing instead from a wide distribution of inter-flash interval timings to produce flashes. When in a collective, however, fireflies influence each other to change their flash timings, eventually reaching a steady state of synchronicity and, impressively, periodicity in their group level flash patterns. The code found here implements the theory presented in https://doi.org/10.7554/eLife.78908 in an agent-based model, suggesting their interactions may follow a simple integrate-and-fire framework where flashes excite neighbors to flash faster than they would normally.

Repository structure:

Simulation.py and Firefly.py are objects used by run.py to instantiate and carry out the logic of the simulation. simulation_helpers.py contains a few helper functions for orchestration and extracting values from the data files mentioned below.

Experimental Data:

Inside the data/experiment folder are the experimental datasets used as input for the model. The envelope_01ff.csv file describes the probability of any one firefly (left column) to choose a particular interflash interval in seconds (right column) and the other files represent the experimentally sampled distributions of interburst intervals in seconds for each of the surveyed densities.

Theoretical Results:

Inside the theory_results folder are results from theoretical calculations. They are structured as probabilities of each inter-burst interval over a range, just like the envelope file.

Simulation Results:

Inside the simulation_results folder are results used for Fig. 2 from simulations at the optimized beta value. These take the form of distributions of inter-burst intervals across 100 trials of the simulation at each of these beta values. Values are in seconds. Additionally, in this folder you can find pickled dictionaries of data from any one output of the simulation you may run.

Agent-Based Model

Main Requirements (versions tested on):

• Python 3.7
• NumPy 1.22.1
• scipy 1.17.1
• pandas 1.3.3
• Matplotlib 3.4.3

The complete list of required packages provided in requirements.txt, which you can install in your environment with the command pip install -r requirements.txt.

Usage:

Default parameters are already set up. To further set up or change parameters for the simulation, a number of flags can be set. Free parameters of the model discussed in the paper:

• n: Number of fireflies in arena (default: 20)
• beta: Donation provided by any one flash (default: 0.2)
• no_refrac: Run with this flag enabled via --no_refrac
• use_linear: Run with this flag enabled via --use_linear
• one_flash: Run with this flag enabled via --one_flash

For a list of customizable flags, please run python run.py -h

python run.py runs a simulation with the default parameters.

Output:

In the folder simulation_results folder there will be a pickle file named to match the density and beta parameters you provided. In here are dictionaries mapping each firefly to its respective a) flash time series (0s and 1s), b) voltage time series (continuous variable between 0 and 1), c) times of flashes (discrete values), d) positions at each itme step (discrete values), which can all be viewed by loading and unpickling the object.