Geraldine Rueda Muñoz - Genetic load accumulation following the founder effect in Heliconius butterflies: a population genomics study on Gorgona island, Colombia

Home institution and supervisors
Camilo Salazar. U Rosario, Colombia.

Host institution and supervisors
José Cerca, Mark Ravinet. UiO, Norway. 2024-2026.
Maëva Gabrielli. Laboratoire EDB, France.

A Heliconius cydno butterfly from Gorgona Island.

Project description
Island colonization often reduces genetic diversity due to founder effects, drift, and unique selective pressures, potentially increasing genetic load. This study examines genetic load in Heliconius cydno subspecies from Gorgona Island, Colombia. Preliminary results reveal low genetic diversity and substantial divergence since colonization. Notably, most individuals were heterozygous for the yellow hindwing bar, regulated by the ivory lncRNA, suggesting this region retains high heterozygosity. The subspecies' distinctive phenotype (yellow-banded forewing with shadow-bar hindwing) may stem from hybridization between H. c. weymeri and H. c. alithea or H. c. zelinde from mainland Colombia. Using demographic analyses and coalescent models, we aim to identify bottlenecks, trace the colonization timeline, and explore hybridization's role in color patterns. These findings may illuminate the evolutionary dynamics of island populations, despite limited adaptability and potential evolutionary stasis.