It was meant to be a grand gesture that would raise the profile of South African science – by allowing fossil bones found at the nation’s Cradle of Humankind site to be flown into space on a Virgin Galactic flight last month. The result was very different. A wave of global condemnation has since engulfed the research team – led by the palaeoanthropologist Lee Berger – that allowed the ancient bones to be used this way. Some scientists raised initial doubts about the fossils’ spaceflight. However, these have since swelled into a tidal wave of criticisms, with leading experts and academic institutions denouncing the incident as “callous”, “unethical”, “extraordinarily poorly thought-out”, “a publicity stunt”, “reckless” and “utterly irresponsible”. Now pressure is mounting to ensure that national and international regulations are strengthened to prevent ancient bones and artefacts of humanity’s predecessors being exploited in this way again. The use of fossils for promotional purposes must never be repeated, say researchers. “At least six national and international bodies have since criticised the space venture, and hopefully nothing like this will ever happen again,” said Professor Chris Stringer of the Natural History Museum in London. This point was backed by Professor Mark Collard, Canada research chair in human evolutionary studies. “Remains of ancient human species are a very limited resource,” he told the Observer last week. “There are very few of them, and the only justification for putting them at risk has to be scientific. That cannot, in any way, be said for this incident.” The specimens – the first ancient hominin remains to leave Earth – consisted of a collarbone of a 2 million-year-old Australopithecus sediba and the thumb bone of a 250,000-year-old Homo naledi. These were carried on the flight – which reached a height of 88km above Earth’s surface on 8 September – by passenger Tim Nash, a South African billionaire. “I am humbled and honoured to represent South Africa and all of humankind as I carry these precious representations of our collective ancestors,” Nash said. The fossils come from species that were first found by teams led by Berger in an area near Johannesburg that is now known as the Cradle of Humankind. Australopithecus sediba was discovered there in 2008 and Homo naledi in 2013. Berger also helped in the selection of the two pieces that were carried by Nash. However, South African scientific rules – like those of other countries – dictate that fossils can only be allowed to travel for scientific purposes and should be securely packed. The two bones, it transpires, were kept in a tube that Nash kept in his pocket as he floated around the cabin of the Virgin Galactic spaceship. “They flew these precious specimens into space, where they could have been destroyed fairly easily,” said Collard. “It was extraordinarily irresponsible. This was done for showmanship, and Berger has got a track record for this sort of thing. “However, the really worrying thing is that the authorities allowed this to happen. They didn’t talk to other people in the field and find out how they would have reacted, and that is the most worrying part of this affair. Individuals make mistakes but you should have a system that prevents that happening. This has to be put right as a matter of urgency.” Berger has since claimed that the decision to send the fossils into space followed careful consideration and in-depth discussions with guiding and regulatory agencies. “All the necessary permissions and permits were acquired, and great care was taken to ensure [the fossils’] safety,” he said. Human origins expert Professor Andy Herries of La Trobe University, Melbourne, disagreed. “This event should trouble anyone worried about the blurring of the lines between legitimate science and using precious fossils for entertainment and promotional purposes,” he told the Observer. Herries said he was particularly concerned because one of the fossils – the collarbone of Australopithecus sediba – was a type specimen. A type specimen acts as a reference against which other pieces of fossil can be compared, and its loss would have been particularly serious, he said. This point was backed by Stringer. “The sediba fossil was historically important because it was the first bone of the species ever discovered, and designated as part of the type skeleton – the scientific reference point that is used to identify the species. Yet it sat in a tube in billionaire Tim Nash’s pockets during the flight. If anything had gone seriously wrong, it would probably have been lost to science for ever.” Stringer added that Berger deserved great credit for the central role he played in the discoveries of Australopithecus sediba and Homo naledi. “But to risk sending fossils from these species to the edge of space was reckless,” he told the Observer. For his part, Berger said that he heard “the concerns raised by the scientific community, which highlight the need for renewed engagement around the processes and permissions to use fossils and heritage artefacts for the public engagement in science”. Nevertheless, he added that scientists were at their best when “we challenge one another to continue to grow and reflect, and I remain committed to ongoing dialogue”. Berger is no stranger to controversy. Earlier this year, he claimed that finds in South Africa’s Rising Star cave system suggested Homo naledi displayed sophisticated behaviour almost a quarter of a million years before modern humans began making graves and art, even though the species had brains little bigger than those of chimpanzees. However, subsequent reviewers later denounced these claims as “imprudent and incomplete”, while others dismissed them as being “largely assumption-based – rather than evidence-based” – and another said that they “do not present convincing evidence”.