Genomic study reveals gradual process of new species formation

An international research team, including scientists from the University of Parma and the University of Puerto Rico, Río Piedras, has published a study in Science Advances regarding the mechanisms of speciation. By analyzing populations of the butterfly Heliconius erato, researchers found that the formation of a new species is not typically the result of a single decisive genetic event.

Instead, the study suggests that speciation emerges gradually through the accumulation of many small or moderate differences distributed across various regions of the genome. Using an innovative pangenomic approach, the team constructed a pangenome of approximately 688 million bases—nearly double the size of previous single reference genomes. This allowed for a more comprehensive view of genetic variability, including regulatory changes that influence gene activity.

The findings indicate that as populations diverge, changes occur not only in DNA sequences but also in the regulatory landscapes that control how genetic information is used. These regulatory shifts contribute to the formation of reproductive barriers by affecting the activation or suppression of specific genes.