Research Square – News/Updates

Reproductive Isolation and Differential Introgression Shape the Genomic Landscape of the Red Alga Amansia Glomerata in the Hawaiian Archipelago

Researchers examined two lineages of the red alga Amansia glomerata around Oʻahu using ddRAD sequencing, spatial transects, and demographic modeling. The study found strong genomic differentiation between lineages even in extensive sympatric zones, supporting allopatric divergence followed by secondary contact driven by Pleistocene sea‑level fluctuations. No recombinant hybrids were observed, indicating robust postzygotic barriers, while introgression was heterogeneous across the genome. These results position Hawaiian seaweeds as a novel model for understanding marine speciation mechanisms.