Insights into human adaptation from ancient DNA

Ancient DNA (aDNA) has revolutionized our ability to study human evolution by enabling the direct observation of genetic changes through time. This has reshaped our understanding of human adaptation and its relevance for modern health and disease. In recent years, high-quality ancient genomes and large datasets have made it possible to track allele frequency dynamics and identify episodes of natural selection with unprecedented resolution. Here, we synthesize insights from recent studies that have systematically investigated how humans adapted to shifts in diet, mobility, pathogen exposure and environment. We summarize the approaches used to detect selection in aDNA, examine the role of major migration and admixture events and connect results across time periods and archaeological contexts. Finally, we outline future challenges and opportunities that need to be addressed for aDNA studies to provide new insights into human adaptation that could not be inferred from present-day genomes alone.