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
Line of purples absent from the gamut of sRGB. Magenta ink, which is one of CMYK's primaries, is also very distant from the Line for the reason explained above. The wide-gamut RGB color space approximates the colors on the Line better, but devices capable of displaying colors with this enhanced system are prohibitively expensive for ordinary consumers. Most of the names of the purple colors in the table below do not denominate colors on the line of purples, but instead are slightly less than maximally colorful, i. e. saturated. Line of purples In color theory, the line of purples or purple boundary is