lifesignaling

Lifesignaling refers to the signals emitted by living organisms that reveal their presence, state, or health. It encompasses a range of observable indicators and is studied across biology, medicine, ecology, and astrobiology. It is related to, but not identical with, the term biosignature, which often emphasizes signs detectable at a distance or in unknown contexts.

Signals can be chemical (metabolites, gases such as CO2 or methane; pheromones), physical (heat emission, movement, infrared), electrical (bioelectrical fields, heart rate, neural activity), acoustic (vocalizations, calls), and visual or behavioral (color changes, posture, activity patterns). Signals may be transient or sustained and can vary with organism, environment, and health.

Applications include medicine, where lifesignals are monitored to assess vital status and disease progression (heart rate, respiration, EEG); ecology and wildlife research, where lifesignaling enables noninvasive tracking through cameras, acoustic sensors, and sensor networks; space exploration and astrobiology, where researchers seek lifesignaling as indicators of life or past life through atmospheric, surface, or thermal signals. In robotics and human–machine interfaces, lifesignaling concepts help detect human presence or intent to inform system responses.

Measurement and interpretation rely on sensors, data acquisition, and signal processing to extract meaningful patterns. Challenges include environmental noise, signal overlap between living and non-living processes, and ethical or privacy concerns when monitoring people or communities. Lifesignaling remains a multidisciplinary framework for understanding how life communicates its presence and state.