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
Blakiston's Line Blakiston's Line The Blakiston Line or Blakiston's Line is a faunal boundary line drawn between two of the four largest islands of Japan: Hokkaidō in the north and Honshū, south of it. It can be compared with faunal boundary lines like the Wallace Line. Certain animal species can only be found north of Blakiston's Line, while certain other species can only be found south of it. Thomas Blakiston, who lived in Japan from 1861 to 1884 and who spent much of that time in Hakodate, Hokkaido, was the first person to notice that animals in Hokkaidō, Japan's northern island, were