Scientists found evolutionary highways in animal genomes dating back 600 million years

Scientists have traced hidden pathways through animal evolution by comparing thousands of genomes and following pieces of chromosomes that have survived for hundreds of millions of years. The study examined 5,821 chromosome-scale genomes from 4,454 species across 19 animal phyla, using 29 ancient linkage groups as markers of chromosome history. Every one of the 406 possible pairings between those ancestral groups appeared somewhere in the dataset, showing how often chromosomes have been joined and reshaped during animal evolution. The resulting genome maps reveal distinct evolutionary trajectories, with some animal groups retaining much of their ancient chromosome structure while others underwent extensive rearrangement.The pace of these changes also varied through time, with chromosome fusions becoming particularly active around 550 million years ago before slowing later. Together, the findings show how ancient chromosome changes can persist, accumulate and influence the routes taken by animal genomes over deep evolutionary time.How ancient chromosomes shaped 600 million years of animal evolutionAccording to the study published in Science Advances, titled ‘Topological mixing and i...