Although a dynamic link between the two innate drives, appetite for food and the urge to reproduce, in vertebrate evolution has been known for a long time, a distinct neurochemical pathway mediating this integration has only recently been appreciated. Study of the precise anatomy of the neural track began in the early to mid 20th century after the sites of genesis of the two instincts were localized to the hypothalamus. This report narrates the birth and fruition to maturity of insights into the commonality of hypothalamic neuropeptide Y (NPY) signaling for the two instinctual drives along two distinct pathways.