Question

Two closely related pigeon breeds differ strikingly in one characteristic: the presence or absence of leg feathers. The leg feathers are black and downy, identical to the feathers that appear on the chest region of both pigeons. What sort of event likely led to the evolution of these leg feathers?

a. A mutation in a protein-coding region of a gene necessary for black downy feather development
b. A mutation in an enhancer or repressor regulating a protein-coding gene necessary for black downy feather development

Answer 1

A mutation in an enhancer or repressor regulating a protein-coding gene likely led to the evolution of leg feathers in closely related pigeon breeds.

Step-by-step explanation:

The likely event that led to the evolution of leg feathers in closely related pigeon breeds is a mutation in an enhancer or repressor regulating a protein-coding gene necessary for black downy feather development. This kind of mutation affects the regulation of gene expression, which determines when and where genes are turned on or off during development. In this case, the mutation would have specifically affected the development of leg feathers, causing them to appear or disappear in different pigeon breeds.