  Recent results from baryon acoustic oscillation measurements by the Dark
Energy Spectroscopic Instrument (DESI) have found preliminary evidence that
dark energy (DE) evolves with time, as parameterized by a $w_0 w_a$ equation of
state. In this study, we point out that the DESI-preferred $w_0w_a$ models are
recovered when a $w_0w_a$ model is fit to DE produced by baryon conversion in
cosmologically coupled black holes (BHs). This recovery does not require any
\emph{ad hoc} parameter adjustments; it solely depends on the independently
measured cosmic star formation rate density. We discuss our result in the
context of the missing baryon problem and the anomalously low sum of neutrino
masses preferred by DESI. The global evolution of DE is an orthogonal probe of
cosmological coupling, complementing constraints on BH mass growth from
elliptical galaxies, stellar binaries, globular clusters, the LIGO-Virgo-KAGRA
merging population, and X-ray binaries. A DE density that correlates with star
formation is a natural outcome of cosmological coupling in BH populations.
