 A second kind of direct evidence that Polger and Shapiro consider is kind splitting in scientific practice. Again, their Official Recipe figures into their response. They reformulate Aizawa and Gillett’s (2011) key example, the variations in cone opsins in human color vision (see discussion in  §3.1  above) into Official Recipe format, and deny that it is a case of genuine multiple realization. The cited differences among the opsins are not distinct from individual differences among those possessing human trichromatic color vision, violating one condition of the Official Recipe.