Why would dark moths have an advantage?

To study these moths, Dr. Kettlewell placed light and dark moths on the trunks of trees where he could observe them. The same birds would find the dark moth twice as often if the bark on the tree was light. This supported the idea that dark moths had a survival advantage in a dark forest.

the missing space is phylum

we need additional information in order to determine the cause of death for anna garcia. there are at least 3 things with explanation included as to why we need them are as follows: