Price, T. ., University of Chicago, Chicago, USA, pricet@uchicago.edu
Ecological and geographical influences on bird speciation
Sister species of birds can show striking ecological differences and occur sympatrically, but many are ecologically very similar and geographically separated (in allopatry or parapatry). Geographically separated sister species are often old and differ predominantly in socially selected traits such as plumage and song; they may continue to hybridize where they meet in parapatric zones of narrow overlap. This suggests speciation processes can be ordered along a continuum, where the time needed for speciation in allopatry is shortened, the greater the differences between the environments that the diverging populations occupy. Using examples from islands and continents (including the Galápagos and the Himalayas), I consider how time in isolation and divergent selection pressures complement each other in promoting speciation. I also argue that these processes do not set the ultimate limit on speciation rate, but rather that is attributed to the ease of range expansions.
Session #:K4Date: 08-15-2009
Presentation is given by student: No
Presenting authors are underlined.