[AndrewC]

Lactose tolerance is the mutation.

I don't think so. Mother's milk is lactose rich. The ability to metabolize the sugar is innate. Look at the computation example for E. Coli. It is in my post 79.

[GourmetDan]

"However, certain human populations have undergone a mutation on chromosome 2 which results in a bypass of the common shutdown in lactase production, allowing members of these populations to continue consumption of fresh milk and other milk products throughout their lives."

http://www.reference.com/browse/wiki/Lactose_intolerance

[muawiyah]

Lactose tolerance is a modern (within the last ten millenia) change in the genome that allows adult humans to digest lactose.

Normal human beings do not have this change.