Wallace Line to the west of the Philippines. Wallace's studies in Indonesia demonstrated the emerging theory of evolution, at about the same time as Joseph Dalton Hooker and Asa Gray published essays also supporting Darwin's hypothesis. Understanding of the biogeography of the region centers on the relationship of ancient sea levels to the continental shelves. Wallace's Line is visible geographically when the continental shelf contours are examined; it can be seen as a deep-water channel that marks the southeastern edge of the Sunda Shelf which links Borneo, Bali, Java, and Sumatra underwater to the mainland of southeastern Asia. Australia is likewise connected
Inter-Entity Boundary Line Inter-Entity Boundary Line The Inter-Entity Boundary Line (, ), commonly abbreviated IEBL, divides Bosnia and Herzegovina into two entities, the Republika Srpska and the Federation of Bosnia and Herzegovina. The total length of the Inter-Entity Boundary Line is . Along the IEBL is the 2 km Zone of Separation, which stretch toward both entities, making the Zone 4 km wide in total. The IEBL essentially runs along the military front lines as they were at the end of the Bosnian War with some major adjustments (most importantly in the western part of the country, and in and around Sarajevo), made