Controversial claims about extinct humans are stirring up evolution research. Here's how the mess could've been avoided

In June, researchers led by palaeoanthropologist Lee Berger published sensational claims about an extinct human species called Homo naledi online and in the Netflix documentary Unknown: Cave of Bones. They argued the small-brained H. naledi buried their dead in Rising Star Cave in South Africa more than 240,000 years ago, and may also have decorated the cave walls with engravings.

If true, this would be an astonishing new entry in the annals of human evolution. But many scientists – including ourselves (the authors of this article, along with Ian Moffat at Flinders University in Australia, Andrea Zerboni at the University of Milan in Italy, and Kira Westaway at Macquarie University in Australia) – are not convinced by the evidence in the three online articles.

The peer reviewers of these articles and the journal editor found that the evidence was “inadequate” and suggested a comprehensive list of changes that would be needed to make the articles’ argument convincing. More recently, a strongly worded, peer-reviewed critique by one of us (Herries) concluded there was not enough evidence to support the hypothesis that H. naledi carried out intentional burials