A species of fly lacks wings. How would biologists explain how a species of fly without wings evolved from an ancestral fly species with wings ?

Ateam from new york presbyterian hospital is conducting a study about a recent increase in cases involving both excess sweating and kidney stones. what would the team need before it draws a conclusion about the cases? medications that are specifically designed to treat the sickness machines that are built to process blood and reduce symptoms until patients are healthy again data that profile the various patients who report these symptoms proof that the excess sweating is related to the excessive kidney stones