New genomic map reveals limited irreversible pathways shaping animal evolution

Scientists from the University of Vienna combined over 5,800 publicly available chromosome-scale genomes representing 4,454 species in a comprehensive analysis, the most extensive of its kind. By arranging these data on a unified framework called evolutionary genome topology, they discovered that animal genomes evolve along a limited number of irreversible pathways, termed “evolutionary highways.” A key mechanism, fusion-with-mixing, merges chromosomes and intermixes genes in a way that cannot be undone, leaving lasting genomic signatures of shared ancestry.

These irreversible events can propel lineages into distinct zones of genome-architecture space, influencing their subsequent evolutionary trajectories. The map also pinpoints groups such as mosquitoes, glass sponges and earthworms that occupy unusually isolated regions of the genomic landscape. Researchers suggest the framework could aid in spotting atypical lineages for deeper study and provide a basis for predicting future directions of genome evolution and biodiversity conservation.