Sir

Your Editorial 'Replicator review' (Nature 450, 457–458; doi:10.1038/450457b 2007), detailing the logic needed to evaluate reports of major research breakthroughs, such as the recent paper on the transfer of nuclear material in a primate, is commendable. It is responsible to require independent confirmation of 'extraordinary claims', in particular for those that are difficult to reproduce.

However, unique materials, such as fossils, require scrutiny by independent researchers to evaluate similarly extraordinary claims. Gaining access to these can be highly problematic. This issue is particularly pervasive in palaeoanthropology, where newly described fossil materials are often barred from review after initial reports. Your News story 'Anthropologists rocked by fossil access row' (Nature 428, 881; 2004) gives one example. Given that Nature is the preferred outlet for analysis of palaeontological discoveries, the editors are in a position to encourage broader access to these valuable specimens.