Pseudo-chemotaxis of active Brownian particles competing for food

TL;DR

This study uses simulations to show that active Brownian particles can exhibit chemotactic behavior in non-stationary environments, allowing them to better locate and fetch food compared to inactive particles, which may have evolutionary advantages.

Contribution

It reveals that active Brownian particles can display chemotaxis in non-stationary conditions, challenging previous beliefs based on stationary system behavior.

Findings

ABPs show chemotactic signatures in non-stationary setups.

ABPs fetch more food than inactive particles in competition.

Active motion provides an evolutionary advantage without sensors.

Abstract

Using Brownian dynamics simulations, the motion of active Brownian particles (ABPs) in the presence of fuel (or 'food') sources is studied. It is an established fact that within confined stationary systems, the activity of ABPs generates density profiles that are enhanced in regions of low activity, which is generally referred to as 'anti-chemotaxis'. We demonstrate that -- contrary to common believes -- in non-stationary setups, emerging here as a result of short fuel bursts, our model ABPs do instead exhibit signatures of chemotactic behavior. In direct competition with inactive, but otherwise identical Brownian particles (BPs), the ABPs are shown to fetch a larger amount of food. From a biological perspective, the ability to turn active would, despite of the absence of sensoric devices, encompass an evolutionary advantage.