NEWS IN FOCUS

HUMAN EVOLUTION Ancient DNA pinpoints dawn of Sequencing of 430,000--old DNA pushes back ’ divergence from .

BY EWEN CALLAWAY de los Huesos (Spanish for ‘pit of bones’), a advanced molecular-analysis techniques. 13-metre-deep shaft in ’s Atapuerca The nuclear DNA, Meyer’s team reports in atthias Meyer has just published the mountains. Few ancient sites are as important on 14 March, shows that the Sima homi- results of what may be the world’s or intriguing as Sima, which holds the remains nins are in fact early Neanderthals. And its age most wasteful genome-sequencing of at least 28 individuals, along with those of suggests that the early predecessors of humans Mproject. In decoding just 0.1% of the genome dozens of and other . The diverged from those of Neanderthals between of the oldest DNA ever recovered from an hominins might have plummeted to their 550,000 and 765,000 ago — too far back ancient , the molecular biologist at the death, but some researchers think they were for the common ancestors of both to have been Max Planck Institute for Evolutionary Anthro- deliberately buried there. heidelbergensis, as some had posited. pology in Leipzig, Germany, threw out enough The Sima hominin skulls have the begin- Researchers should now be looking for raw data to map the modern human genome nings of a prominent brow ridge, as as a population that lived around 700,000 dozens of times over. to 900,000 years ago, says But the excess was necessary, Martinón-Torres. She thinks that because the DNA in the Homo antecessor, known from 430,000-year-old bones was 900,000-year-old remains from degraded and contaminated. Meyer’s Spain, is the strongest candidate feat of recovery has revealed that the for the common ancestor, if such remains, from a cavern in northern specimens can be found in Africa Spain, represent early Neanderthals or the Middle East. — and has pushed back estimates The team’s latest mitochondrial of the time at which the ancient sequences, meanwhile, again con-

predecessors of humans must have firm the puzzling link between TRUEBA, MADRID SCIENTIFIC FILMS JAVIER split from those of Neanderthals the Sima hominins and the Den- (M. Meyer et al. Nature http://dx.doi. isovans. Meyer suggests that the org/10.1038/nature17405; 2016). ancestors of the two groups car- “Starting such a thing is already ried mitochondrial DNA that is very ambitious, and managing reflected in both — but which is it is even more impressive,” says Bone powder from the of a 430,000-year-old ‘Sima’ skeleton. not present in later Neanderthals. Ludovic Orlando, an ancient-DNA This elimination could have hap- researcher at the Natural History Museum other traits typical of Neanderthals. But other pened by chance, but Meyer now favours the of Denmark in Copenhagen. “We are really features, and uncertainties around their age hypothesis that an as yet unknown species reaching the limits of what is possible.” — some studies put them at 600,000 years from Africa migrated to Eurasia and bred with The analysis addresses confusion over old, others closer to 400,000 — convinced Neanderthals, replacing the mitochondrial which species the remains belong to. A report many researchers that they might instead DNA lineages. (Supporting this idea, stone- published in 2013 sequenced a femur’s mito- belong to an older species known as Homo tool spread from Africa to Eura- chondrial genome — which is made up of heidelbergensis. sia around half a million years ago, and again DNA from the cell’s energy-producing struc- Confusion peaked when Meyer, his col- 250,000 years ago). tures that is more abundant in cells than is league Svante Pääbo and their team revealed It is hard to rule out these or other ideas nuclear DNA. It suggested that at least one the mitochondrial connection to the Den- without new data, says Meyer. The full or individual identified from the remains was isovans. But they hoped that retrieving the nearly full genome of a Sima hominin, or more closely related to a group called Den- skeletons’ nuclear DNA — which represents genetic data from other early Neanderthals, isovans — known from remains found thou- many more lines of ancestry than does mito- would be necessary. sands of kilometres away in Siberia — than chondrial DNA, which is inherited solely from “It’s fascinating and keeps us all on our it was to European Neanderthals (M. Meyer the maternal line — would clear things up. toes trying to make sense of it all,” says Chris et al. Nature 505, 403–406; 2014). Stringer, a palaeoanthropologist at the Natu- “It’s wonderful news to have mitochondrial NUCLEAR RECOVERY ral History Museum in London. Stringer says and nuclear DNA from something that is Meyer’s team managed to glean nuclear and that the recovery of such old nuclear DNA 430,000 years old. It’s like science fiction. It’s an mitochondrial DNA from five Sima samples, gives him hope that researchers will be able to amazing opportunity,” says Maria Martinón- probably representing different individuals. A analyse ancient DNA that stretches even fur- Torres, a palaeoanthropologist at University key factor in their success, says Meyer, was that ther back in time. “Instead of just being stuck College London. since 2006, archaeologists had carefully refrig- with trying to resolve the last 100,000 years,” The remains are known as the Sima erated teeth and shoulder- tissue from the he says, “we can really start to put some dates hominins because they were found in Sima pit to preserve the ancient DNA — awaiting from DNA further down the human tree.” ■

286 | NATURE | VOL 531 | 17 MARCH 2016 © 2016 Macmillan Publishers Limited. All rights reserved