Unformatted text preview: from other such groups." Under the BSC…”the central problem of SPECIATION is
understanding the origin of isolating barriers* that actually
or potentially prevent gene flow in sympatry.” (Coyne and
Orr 2004). *isolating barriers = phenotypes, e.g. behaviors! 8 9/19/13 Can behavioral barriers initiate speciation? Can behavioral barriers initiate speciation? YES 9 9/19/13 How do we study speciation? !
(Shaw and Mullen 2011)"
" • Axes of differentiation—will tell us all the ways that
closely related species differ"
• Speciation phenotypes—will tell us which
phenotypes prevent gene ﬂow"
• Forces of differentiation—will tell us why these
phenotypes evolved (diverged)"
• Genetic architectures of speciation—will tell us
what underlying genetic changes occurred"
• The evolution of species boundaries—will tell us
how speciation phenotypes trigger further genome
evolution" Speciation model for Laupala crickets Axes of differentiation Speciation phenotype Divergent acoustic behavior!
between populations due to
acoustic differences !
Reproductive isolation! Hypothesizes that acoustic evolution causes "
speciation in Hawaiian crickets 10 9/19/13 Some Natural History
Hawaiian Islands are super isolated! And a great laboratory for the study of speciation: Geology and Evolution Direction Of
Plate Movement 11 9/19/13 Some Natural History
(5.1 my) (0.75-1.9 my) (0.43 my)! Some Natural History R. C. L. Perkins (British Museum) Dan Otte (Philadelphia Academy) Genus Laupala (swordtail crickets) before 1994: 1 species formally recognized after 1994: 38 species formally recognized 12 9/19/13 L. cerasina 100
94 Laupala 100
97 L. fugax
Maui! Oahu! L. melewiki 91
73 Kauai! L. eukolea 100 65 L. spisa 100 L. neospisa 71 L. hapapa
L. oahuensis Hawaii! L. pacifica 100 Laupala AFLP NJ tree/bootstraps 1048 characters L. hualalai 100
95 L. pruna 100
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- Fall '10