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
History of the South Island line and West Island line History of the South Island line and West Island line The history of the South Island Line and West Island Line encompasses a number of proposals which were made for extending the Hong Kong MTR metro system to the south and west of Hong Kong Island, which were not serviced by any rail transport before 2014. The West Island Line opened as an extension of the Island Line on 28 December 2014. The South Island Line has completed construction and commenced service on 28 December 2016. The proposed South Island Line (West) is still in the planning phase and is