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
Dwane Wallace After the war, Wallace quickly developed an all-metal replacement of the C-34—the Cessna 190 / Cessna 195, a speedy 6-seat, single-engine, executive aircraft, powered by a large, traditional radial engine. Wallace then guided Cessna away from the pioneering un-braced "cantilever"-wing design concepts of Clyde Cessna, towards more conservative-and-traditional, "strut-braced," high wings—producing the world's most successful line of single-engine light aircraft, ranging through numerous variants from the Cessna 120/Cessna 140 to the Cessna 207—despite the industry's move towards cantilever wings. The 120/140 also was the beginning of Cessna's conversion to smaller-cabin aircraft with streamlined, flat, horizontal-cylinder engines. The 120/140's distinguishing feature,