Critics rain on H. naledi team’s parade
J ohannesburg - Scientists who on Wednesday announced the discovery of a new species of human relative have defended their groundbreaking find.
As an acclaimed palaeontologist and archaeologist, team leader Professor Lee Berger has not let his detractors rain on his parade.
International critics questioned why Berger hadn’t dated the findings, and said Homo naledi may be a species of Homo erectus, and not a new species of human relative.
On Wednesday the global spotlight fell on South Africa when the group unveiled the new species who, remarkably, buried their dead.
The announcement, at the Maropeng visitors’ centre near Krugersdorp, was that in a remote cave chamber named Dinaledi, the largest number of hominin fossils in Africa had been found.
According to Berger and his team of 60 scientists, Homo naledi is believed to sit at the start of the human genus and will probably reveal more about the beginnings of our evolutionary journey.
But a shadow has been cast on one of Africa’s biggest discoveries with US palaeoscientist Professor Tim White calling the conclusions “speculation” in an article in the online publication Wild on Science.
However the main concern around the discovery is that there is no date attached to the findings.
Swiss professor Christoph Zollikofer, from the Anthropological Institute at the University of Zurich, was quoted in the article as saying if there was no serious attempt to date the site, it would be difficult to draw any conclusions.
Asked why the fossils hadn’t been dated, Berger said: “We didn’t feel it ethical to destroy hominin material until it had been described; dating the specimen would mean the destruction of the material.”
Berger said he would not be drawn into speculation on their age, insisting the discussions were based on morphology and that the question of age should not be used to contaminate the discovery.
“These are the most identical hominins ever discovered.”
He said the specimens found were so similar to each other, they could even be from the same family or of the same genetic line.
But the idea of adding a new species to the evolutionary tree is regarded by some as controversial.
White claims Homo naledi is more likely to be an example of Homo erectus. When five Homo erectus fossils were found in Dmanisi, Georgia, in 2013, there was an uproar in the scientific community.
The researchers, including Zollikofer, found as many variations between individuals in Homo erectus as there are in modern humans.
They have argued many of the unique species discovered in Africa, such as Homo habilis and Homo rudolfensis, are part of the same species lineage.
Despite his concerns about the lack of dating, Zollikofer said the Homo naledi find adds to the argument that human evolution didn’t occur in a single motion. “It is something that happens slowly, slowly over time. It’s fantastic that Berger finds new fossils in these quantities, it’s not easy to do.”