Where does etiology / aetiology collide?

In the philosophy of biology, the etiological theory of function holds that the function of a trait is the effect it was selected for: what a heart is for is pumping blood, because pumping blood is why hearts were favoured and passed on, so the trait's causal history explains why it exists. Function on this account is not whatever a part happens to do now, but the past effect that accounts for its being there at all. Wright's 1973 Functions gave the founding statement of this backward looking analysis, and Neander's 1991 Functions as selected effects tied it explicitly to natural selection. The word here names a theory of purpose grounded in evolutionary history, not the cause of an illness in a patient, and not a folk story that explains an origin.[1][2]

Unit

One trait's function, fixed by the past selection that explains its presence

Recovery means

Not applicable

Measured by

Argued from a trait's selective history and the contribution to fitness that caused it to spread

In folklore and religious studies, an etiological myth is a traditional story told to explain the origin of something: how a place got its name, why a ritual is performed, or where a custom or a natural feature came from. The narrative answers a question of why something is as it is, or how it first began, by tracing the thing back to an event in a mythic past. Bascom's 1965 The forms of folklore: Prose narratives placed such origin explaining tales within the wider class of myth and described their role in accounting for the world as people find it. The word here names a kind of explanatory story handed down in a culture, not the cause of a disease, and not the evolutionary purpose a biological trait was selected for.[3]

Unit

One traditional narrative that accounts for a single origin

Recovery means

Not applicable

Measured by

Identified by collecting and comparing traditional narratives and the origins they claim to explain