In this Special Issue of Science, three Reviews highlight how recent advances in the field of ancient DNA have greatly advanced our understanding of the evolutionary history of many plants and animals, including our own species. "This special issue examines the changing landscape of how ancient DNA (aDNA) is studied today, including previously untapped sources, improvements in technology, and ethical challenges, and what we've learned about ourselves though ancient DNA," write Corinne Simonti and Madeleine Seale, associate editors at Science.
In one Review, María Ávila-Arcos and colleagues discuss the significance of aDNA in addressing non-European regional questions. According to the authors, much of the early human aDNA research was focused on large-scale events, such as continental-scale population migrations or genetic admixture events, with an overrepresentation of European-focused studies. However, many regional questions, particularly those relevant to the Global South, remain underexplored. By reviewing several recent paleogenomics studies that have been successful in highlighting local histories and health in the Americas, Africa, Asia, and Oceana, particularly that of the Indigenous and Descendant communities that live there, Ávila-Arcos et al. underscore the importance of bringing a regional perspective to aDNA research. They further explore the ethical considerations as the field shifts towards answering finer-scale questions. When done correctly, finer-scale aDNA investigations can be a powerful tool with the potential to integrate neglected or oppressed communities and to uncover past histories that have been lost or erased from history.
Another Review, by Hernán Burbano and Rafal Gutaker, discusses the use of aDNA from herbarium specimens – historically collected and preserved plant samples – to provide glimpses into past plant communities. Such insight can provide a better understanding of the evolutionary and ecological processes that shape plants over time and could help inform new conservation efforts. In a third Review, Beth Shapiro and colleagues explore the state-of-the-art in paleogenomics techniques and discuss the key challenges that remain, including technical limitations that impede the ability to evaluate "deep-time" ancient DNA.
