An evolutionary tree based on DNA sequences of silversword alliance members shows how current species are descended from a common ancestral species. Only some of the known species are shown here. Letters following each species indicate the island or islands on which the species grows today (K = Kauai; O = Oahu; M = Maui, Lanai, and Molokai; and H = the Big Island of Hawaii). According to the DNA data, the ancestral species split into two separate species approximately five million years ago. One of these species eventually gave rise to the Argyroxiphium species that now grow on Maui and the Big Island. The other species evolved into the two Wilkesia species that today are found on Kauai and the 23 Dubautia species found on all the islands. (Diagram adapted from Bruce G. Baldwin and Michael J. Sanderson, “Age and Rate of Diversification of the Hawaiian Silversword Alliance (Compositae),” Proceedings of the National Academy of Sciences 95:9402-9406, 1998.)



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