[allmendream]

Easy. Do most mammals ever get a chance to drink milk other than in infancy? Why waste resources making an enzyme (lactase) that would never be of any use?

It took domestication of milk giving animals before a mutation of this proximal region to the lactase gene would be an advantage; and apparently it arose at least twice independently, once among Northern Europeans, and again among cattle herding Africans (they have different mutations).

[AndrewC]

Why waste resources making an enzyme (lactase) that would never be of any use?

So you are saying that lactase is of no use?

[ElectricStrawberry]

Whoa whoa whoa....stop with the evidence already.....you’re eve making ME dizzy...