With every advance in sequencing technology, researchers are examining older and more challenging samples to study ancient organisms, including humans, writes Nature's Ewen Callaway.
In the past few years, by making tweaks to protocols, the University of Copenhagen's Ludovic Orlando and colleagues were able to sequence a 700,000-year-old horse while Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology and his team sequenced 400,000-year-old hominin remains.
The horse sample, Callaway noted, was waiting in a freezer for the technology to advance.
While some researchers are turning to even older samples from permafrost and other well-preserved sites, Pääbo and his colleagues are interested in trying to scrape DNA and maybe a genome out perhaps more recent samples, but ones from warmer parts of the world where DNA degrades more quickly.
Others, though, note that samples aren't strictly required to study ancient organisms. Hidden within the genomes of modern humans, for instance, are 'ghosts' of bygone peoples, bits of genes from ancient hominins that modern humans have inherited.
As the field matures, Callaway adds that it is opening up to non-specialists and exploring different questions, such as the advent of agriculture or the domestication of dogs.