The Menk are one of the two native species located on the planet Valakis. The Menk are less evolved then the Valakians.
The Valakians provide the Menk with food, clothing, and other needs. The Valakians treat the Menk with little respect.
Humans made first contact with the Menk in 2151 when the NX-01 Enterprise picked up a Valakian ship and returned them to their homeworld.
The crew of the Enterprise discovered that the Valakians were being wiped out by a genetic disorder. Dr. Phlox had to make a decision rather to help the Valakians. He discovered the the the Menk were on the verge of a evolutionary breakthrough.