Specie e speciazione

Speciazione allopatrica per dispersione (spec. peripatrica) in drosofile hawaiane
• Over 500 endemic species in 2 genera
• Occupy a wide variety of ecological niches
• Many species have ranges restricted to single islands
• One of the most famous adaptive radiations
• “Founder hypothesis” – one gravid female (or a few individuals) disperse to another island and
start a new isolated population
• Predictions:
– Closely related species should tend to be on neighboring islands
– At least some phylogenetic branching sequences should correspond to the sequence in which
islands were formed
DeSalle and Giddings 1986)