A Sexual Cosmos

Evolutionary cosmology has, without remarking on it, been a theory of clonal reproduction: in Cosmological Natural Selection (CNS) each universe has one parent, copies it with small variation, and is sorted by selection on black-hole fecundity. We argue that two-parent cosmogenesis — in which a child is the joint issue of two daughters’ fused throats — is not a tougher version of that theory but a change in reproductive mode, from the clonal to the sexual; and that the change relocates the defining events. In a clonal world, selection across deep time is the whole story. In a sexual world, the events that decide what exists are local and per-pairing: whether two given universes are compatible enough to produce a child at all, and whether the particular child is viable. We take the bold reading honestly: the fine-tuning that motivates a multiverse suggests the cosmic lawbook is wound tight, but whether that thinness entails the coadaptation that would make most pairings barren is the essay’s central open question — we isolate the gap rather than cross it. We show that three standard objections (no genome, no selectable gap, recombination load) are one parameter — the coadaptation of the lawbook — read three ways, and make that single computable knob the program’s centre. We credit the prior coinage of “cosmological sexual selection” (Vidal 2014) and stop, deliberately, one step short of the inference that intelligence is therefore the author of universes. Revision history. SC 1.0 → SC 2.0 (June 2026). Coadaptation was defined precisely as the off-diagonal extrinsic curvature of the viable boundary in the projected constant-aligned frame, distinguishing it from the population-genetics usage. The sibling constraint was reframed as the paper’s central structural limit: the merging black holes share the same parent universe, so their constant-sets differ only by small bounce-mutation increments, not by the large divergence that would make most crossings fail. The headline claim — that most cosmic pairings should be sterile — was retracted as overclaiming; the honest statement is that whether pairings fail is an open geometric question whose answer is not settled by fine-tuning alone.