Wallace Line by the Sahul Shelf to New Guinea. The biogeographic boundary known as Lydekker's Line, which separates the eastern edge of Wallacea from the Australian region, has a similar origin to the Wallace line. During ice age glacial advances, when the , both Asia and Australia were united with what are now islands on their respective continental shelves as continuous land masses, but the deep water between those two large continental shelf areas was, for over 50 million years, a barrier that kept the flora and fauna of Australia separated from those of Asia. Wallacea consists of islands that were not
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,