Information Transmission via Molecular Communication in Astrobiological Environments.

The ubiquity of information transmission via molecular communication between cells is comprehensively documented on Earth; this phenomenon might even have played a vital role in the origin(s) and early evolution of life. Motivated by these considerations, a simple model for molecular communication entailing the diffusion of signaling molecules from transmitter to receiver is elucidated. The channel capacity (maximal rate of information transmission) and an optimistic heuristic estimate of the actual information transmission rate are derived for this communication system; the two quantities, especially the latter, are demonstrated to be broadly consistent with laboratory experiments and more sophisticated theoretical models. The channel capacity exhibits a potentially weak dependence on environmental parameters, whereas the actual information transmission rate may scale with the intercellular distance as ∝ and could vary substantially across settings. These two variables are roughly calculated for diverse astrobiological environments, ranging from Earth's upper oceans ( ∼ 3.1 × 10 bits/s; ∼ 4.7 × 10 bits/s) and deep sea hydrothermal vents ( ∼ 4.2 × 10 bits/s; ∼ 1.2 × 10 bits/s) to the hydrocarbon lakes and seas of Titan ( ∼ 3.8 × 10 bits/s; ∼ 2.6 × 10 bits/s).