From what I’ve read the evolution of adult lactase was almost instant. Humans naturally produce lactase as babies, but what had to happen was to extend that pro

From what I’ve read the evolution of adult lactase was almost instant. Humans naturally produce lactase as babies, but what had to happen was to extend that production into adulthood. This is really a straightforward mutation then, what had changed was the non silencing of the gene that is already active at birth.