The Libido-Related Darwinian Adjunct Theory of Evolution

We propose the Libido-Related Darwinian Adjunct Theory (LRDAT): some genetic variants that restrict oxygen delivery or cellular energy supply, and so predispose to disease, may persist partly because brief oxygen and glucose depletion intensifies the experience of orgasm, with constriction of blood vessels playing the central role. The theory is offered as an adjunct to, not a replacement for, natural selection. It reads these variants as cases of antagonistic pleiotropy in which sexual reward is traded against long-term health. The sickle-cell allele (HbS) is the worked example: LRDAT adds a sexual-reward benefit to the well-established protection that HbS carriers gain against falciparum malaria. A second claim, "ischemic mimicry", holds that chronic vasoconstriction in conditions such as hypertension, asthma and some neurodegeneration reproduces, at low intensity and without sexual context, the vascular and metabolic state of orgasm. The relationship is graded: moderate constraint is predicted to raise reward and severe disease to lower it, so the theory covers mild to moderate forms of these conditions only. The model yields six predictions, each testable with existing methods: (1) chronic energetic constraint co-varies with sexual function; (2) obstetric markers of early pressure stress predict adult vascular tone and sexual function; (3) genes for vascular tone and metabolism show pleiotropic links to sexual-reward traits; (4) mild, safe oxygen or glucose challenges modestly raise arousal and reward; (5) carriers of one HbS allele show a sexual-reward advantage that is independent of malaria exposure; (6) vasoconstriction mediates the effect. Consistent null results on the main predictions would count against the theory. The evolutionary claim is speculative and is presented as a hypothesis for scrutiny, not as established fact.