A multi-million-year natural experiment

Improving the diversity and quality of genome assemblies for non-human mammals has been a long-standing goal of comparative genomics. The last year saw substantial progress towards this goal, including the release of genome alignments for 240 mammals and nearly half the primate order. These resources have increased our ability to identify evolutionarily constrained regions of the genome, and together strongly support the importance of these regions to biomedically relevant trait variation in humans. They also provide new strategies for identifying the genetic basis of changes unique to individual lineages, illustrating the value of evolutionary comparative approaches for understanding human health. A recent analysis of hundreds of mammalian genomes, including many of our closest primate relatives, has identified unusual regions of the genome that have remained nearly unchanged over hundreds of millions of years of evolution. These regions are frequently biomedically relevant, showcasing the importance of evolutionary analysis for understanding human health.