RESUMO
The importance, extent, and mode of interspecific gene flow for the evolution of species has long been debated. Characterization of genomic differentiation in a classic example of hybridization between all-black carrion crows and gray-coated hooded crows identified genome-wide introgression extending far beyond the morphological hybrid zone. Gene expression divergence was concentrated in pigmentation genes expressed in gray versus black feather follicles. Only a small number of narrow genomic islands exhibited resistance to gene flow. One prominent genomic region (<2 megabases) harbored 81 of all 82 fixed differences (of 8.4 million single-nucleotide polymorphisms in total) linking genes involved in pigmentation and in visual perception-a genomic signal reflecting color-mediated prezygotic isolation. Thus, localized genomic selection can cause marked heterogeneity in introgression landscapes while maintaining phenotypic divergence.
Assuntos
Corvos/genética , Plumas/citologia , Fluxo Gênico , Variação Genética , Melanócitos/enzimologia , Pigmentação/genética , Animais , Evolução Molecular , Plumas/enzimologia , Genômica , Hibridização Genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Seleção GenéticaRESUMO
We investigate the spatial structure of broad-area vertical-cavity regenerative amplifiers injected with a homogeneous beam. The emerging patterns have a predominantly sixfold rotational symmetry, verifying the recent prediction of formation of hexagons. The length scale is controllable by means of detuning and follows the prediction for tilted waves.
