This will bring up a GenerationView window. Everything should be pretty self explanatory. You may select and unselect pictures by clicking on them. Some toolbar buttons will only be enabled when a certain number of pictures are selected. For example, you may only View and Replace when one picture is selected, to indicate which picture is to be viewed or replaced.
Breeding requires having two or more pictures selected.
Back and Forward will be enabled only when there exists a previous or future generation. You may also navigate around generations by clicking on the Go menubar . The Breed To Target image should change. Now click the Breed button right below it. This will automatically select the best images to breed and return a new Generation in the Generation View.