The geometry and genetics of hybridization.

摘要: When divergent populations form hybrids, hybrid fitness can vary with genome composition, current environmental conditions, and the divergence history of populations. We develop analytical predictions for fitness, which incorporate all three factors. The are based on Fisher's geometric model, apply to a wide range population genetic parameter regimes including allopatry parapatry, local adaptation, drift. Results show that be decomposed into intrinsic effects admixture heterozygosity, extrinsic (local) adaptedness parental lines. Effect sizes determined by handful distances, have simple biological interpretation. These distances also reflect mode amount divergence, such there is convergence toward characteristic pattern isolation. next connect our results quantitative genetics line crosses in variable or patchy environments. This means geometrical estimated from cross data, provides interpretation "composite effects." Finally, we extensions involving selectively induced disequilibria, phenotypic dominance. geometry landscapes unifying framework understanding speciation, wider patterns hybrid fitness.