| Autor: |
Langdon QK; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C.; Gladstone Institute of Virology, Gladstone Institutes, San Francisco, California., Groh JS; Center for Population Biology and Department of Evolution and Ecology, University of California, Davis., Aguillon SM; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C.; Department of Ecology and Evolutionary Biology, University of California, Los Angeles., Powell DL; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C., Gunn T; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C., Payne C; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C., Baczenas JJ; Department of Biology, Stanford University., Donny A; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C., Dodge TO; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C., Du K; Xiphophorus Genetic Stock Center, Texas State University San Marcos., Schartl M; Xiphophorus Genetic Stock Center, Texas State University San Marcos.; Developmental Biochemistry, Biocenter, University of Würzburg., Ríos-Cárdenas O; Red de Biología Evolutiva, Instituto de Ecología, A.C., Gutierrez-Rodríguez C; Red de Biología Evolutiva, Instituto de Ecología, A.C., Morris M; Department of Biology, Ohio University., Schumer M; Department of Biology, Stanford University.; Centro de Investigaciones Científicas de las Huastecas 'Aguazarca', A.C.; Freeman Hrabowski Fellow, Howard Hughes Medical Institute. |
| Abstrakt: |
Over the past two decades, evolutionary biologists have come to appreciate that hybridization, or genetic exchange between distinct lineages, is remarkably common - not just in particular lineages but in taxonomic groups across the tree of life. As a result, the genomes of many modern species harbor regions inherited from related species. This observation has raised fundamental questions about the degree to which the genomic outcomes of hybridization are repeatable and the degree to which natural selection drives such repeatability. However, a lack of appropriate systems to answer these questions has limited empirical progress in this area. Here, we leverage independently formed hybrid populations between the swordtail fish Xiphophorus birchmanni and X. cortezi to address this fundamental question. We find that local ancestry in one hybrid population is remarkably predictive of local ancestry in another, demographically independent hybrid population. Applying newly developed methods, we can attribute much of this repeatability to strong selection in the earliest generations after initial hybridization. We complement these analyses with time-series data that demonstrates that ancestry at regions under selection has remained stable over the past ~40 generations of evolution. Finally, we compare our results to the well-studied X. birchmanni×X. malinche hybrid populations and conclude that deeper evolutionary divergence has resulted in stronger selection and higher repeatability in patterns of local ancestry in hybrids between X. birchmanni and X. cortezi . |
