Proximate & Ultimate Medicine
Extending Tinbergen’s Framework from Explanation to Intervention
Paper in preparation · Target journal: Evolution, Medicine and Public Health
The problem
Evolutionary medicine, first articulated by Nesse and Williams, explains why natural selection leaves humans vulnerable to disease — distinguishing proximate mechanisms from ultimate evolutionary causes, following Tinbergen's four questions. A persistent critique is that the field remains largely explanatory rather than clinically transformative. Clinicians who accept the evolutionary account of a condition still tend to return, by default, to proximate-level interventions.
The distinction
This framework extends Tinbergen's proximate–ultimate distinction from disease aetiology to clinical action. Just as disease can be understood at the level of mechanism or of evolutionary cause, interventions can be classified by the causal depth at which they operate.
Proximate medicine acts on the mechanisms of disease expression — pharmacological, surgical and procedural.
Ultimate medicine acts on the evolutionary mismatch conditions that generate vulnerability in the first place. This is a claim about specific, identifiable mismatches, not a general claim that ancestral life was healthier.
Why both
The two categories are complementary, not competing. Proximate interventions act rapidly and are essential for stabilising acute derangements. Ultimate interventions act slowly, because they target the conditions that shaped the evolved architecture of those mechanisms. Proximate medicine often functions as a stabilising bridge while ultimate medicine does the slower work.
Acute and chronic describe duration; proximate and ultimate describe causal depth. They are not the same distinction.
Proximate medical and pharmacological care remains the province of medical practitioners. The framework treats it as necessary, not as something to be replaced.
Status
A manuscript setting out the classification in full — including its application across the categories of evolutionary medicine, and a worked example — is in preparation for submission to a peer-reviewed journal. This page is a summary. The framework is a proposed classification, not an established one, and is not offered as a clinical service.
The evolutionary hypothesis underpinning the Neurolithic Diet is developed on the LEMH page.
Chimpanzees in the Mahale Mountains have been observed deliberately consuming bitter plant material with no nutritional value but documented antiparasitic and anti-inflammatory properties. This is proximate medicine — targeted intervention against a discrete threat, deployed while the ultimate substrate remains intact.
Photo: Eric Kamoga / Pexels
Academic status Proximate and Ultimate Medicine: Extending Tinbergen’s Framework from Explanation to Intervention (Glanville, in preparation) — Commentary, in preparation for submission to Evolution, Medicine and Public Health (Oxford University Press). The companion paper, LEMH, is deposited as a preprint at Zenodo (doi.org/10.5281/zenodo.20681888; not peer-reviewed).
Why the distinction matters
The value of the distinction is descriptive: it makes it possible to say what a given intervention is actually doing — acting on the mechanism of a problem, or on the conditions that generated it. Both are legitimate, and neither substitutes for the other.
That clarity matters for research, because interventions of the two kinds need to be evaluated differently and on different timescales. It also matters for expectations: an intervention working at one level should not be judged by what would count as success at the other.
Proximate medical and pharmacological care sits with your GP and wider clinical team. The framework treats it as necessary, not as something to be replaced.
The evolutionary hypothesis underpinning the Neurolithic Diet is developed in full on the LEMH page.
