Why was the genetic information from the distantly related cormorant unusable for this research? Why was it important for genetic comparison to find a closely related cormorant species?

Species which are distantly related have fewer similarities in the genetic information present in them. Species that are closely related will have more similar genetic codes producing many similar proteins and share many genetic similarities. Hence, in order to understand about the specific changes which caused a certain feature to appear or disappear, one must compare it with species which are closely related rather than the ones which are distantly related.