Another evolutionary paradigm: the Hawaiian islands . Again the islands are young (< 5 million years old), have a volcanic origin and an interesting one: convection currents in the earth's mantle generate a "hot spot" where volcanic activity occurs above. The pacific plate moves northwest over this spot so the islands' geographical location is related to their age (Kauai in the north west is ~ 5 million years old; Hawaii [the big island] in the southeast is ~ 500,000 years old and still active ). Hawaiian Drosophila show remarkable patterns of colonization and speciation. At least 700 species of Drosophilids on Hawaiian islands. Not just typical little fruit flies either: large body size, dramatic "picture wing" species, some with "hammer-head" shaped heads. Banding patterns of polytene chromosomes allows phylogeny reconstruction: these and other data show that patterns of colonization are from older to younger islands (flies on Hawaii are derived from ancestors on Maui). Most species
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This note was uploaded on 11/06/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.