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
Brett Wallace minor-league contract including an invitation to major-league spring training with the San Diego Padres. On June 19, 2015, the Padres called Wallace up. He finished the season with a .302/.374/.521 slash line in 107 plate appearances for the Padres. The following off season, the Padres and Wallace avoided arbitration by agreeing to a $1 million contract for 2016. Wallace was given the starting third base job when Yangervis Solarte was placed on the disabled list with a hamstring injury. Wallace failed to repeat his 2015 production in 2016, finishing the season with a .189/.309/.318 slash line in 256 plate appearances.