[allmendream]

My answer was not so lengthy that you needed to abridge it. It was clear from my context that lactase is only of no use to something without access to a ready supply of milk.

Most adult mammals will never get an opportunity to drink milk, so no, a lactase gene would be of no use.

To a nursing mammal it is of primary importance.

To a human with cattle it is a distinct advantage to have this mutation.

So much for the ‘no advantage to any change in DNA’ idiocy.

[AndrewC]

Most adult mammals will never get an opportunity to drink milk, so no, a lactase gene would be of no use.

B.S. They are called mammals for a reason. Milk is readily available where there are mammals. A nursing mammal is merely a mammal that drinks milk. As long as a female is capable of giving birth lactose can be used. So don't beg the question. Does lactase have a use? And I did not abridge what your conclusion was.