CONCEPT
Umwelt
Jakob von Uexküll's 1934 concept for the subjective world of an organism — constituted by the specific signals it can detect and the specific responses it can perform. The tick's world is butyric acid, warmth, and blood chemistry; the forest is not part of it.
The biologist Jakob von Uexküll coined the term Umwelt (German: "surrounding world" or "environment-as-experienced") to name the subjective world each organism inhabits. The tick's Umwelt is not the forest. It is not the branch, the wind, the sunlight, the other insects, the soil composition. The tick's Umwelt is three signals: butyric acid (the compound released by mammalian skin glands), warmth (indicating a living host), and the chemical signature of blood. Everything else is not merely irrelevant to the tick — it does not exist for the tick. The tick does not ignore the forest; the forest is not part of the tick's enacted world.
In The You On AI Field Guide
Varela drew extensively on Uexküll's framework in developing the enactive approach. The Umwelt concept provided a rigorous biological grounding for the claim that the world of significance is not pregiven but enacted. Different organisms inhabit different Umwelten; there is no