| Popis: |
Hybrid zones are dynamic systems where natural selection, sexual selection and other evolutionary forces can act on reshuffled combinations of two distinct genomes. The movement of hybrid zones, individual traits, or both are of particular interest for understanding diversification processes. In a hybrid zone involving two lek-breeding birds (genusManacus), secondary sexual plumage traits ofM. vitellinus,especially bright yellow collars and olive bellies, have introgressed asymmetrically ∼50 km across the genomic center of the zone into populations ofM. candei. Males with yellow collars are preferred by females and are more aggressive than parentalM. candei, suggesting that sexual selection was responsible for the introgression of male traits. To assess the spatial and temporal dynamics of this hybrid zone, we carried out a longitudinal reassessment using historical (1989 - 1994) and contemporary (2017 - 2020) transect samples to survey both morphological and genetic variation. Genome-scale SNP data and several male phenotypic traits show that the genomic center of the zone has remained spatially stable, whereas the olive belly color of malevitellinushas continued to introgress over time, suggesting that sexual selection may be an ongoing evolutionary force in this system. |
