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
Simson line Simson line In geometry, given a triangle "ABC" and a point "P" on its circumcircle, the three closest points to "P" on lines "AB", "AC", and "BC" are collinear. The line through these points is the Simson line of "P", named for Robert Simson. The concept was first published, however, by William Wallace in 1797. The converse is also true; if the three closest points to "P" on three lines are collinear, and no two of the lines are parallel, then "P" lies on the circumcircle of the triangle formed by the three lines. Or in other words, the Simson