According to Monday’s study, fossils of human ancestors from the early days of humanity found in South African cave systems may be one million years older than originally thought.
According to the Proceedings of the National Academy of Sciences journal, they could be between 3.4 million and 3.6 million years of age. This is more than the time that Ethiopia’s famous Lucy or Dinkinesh fossil was discovered in 1974. It dates back to 3.2million years.
The Sterkfontein Caves are located 30 miles north of Johannesburg and contain ancient hominin fossils. They form part of a UNESCO World Heritage Site called the Cradle of Humankind. The hominins are humans and our ancestral relatives. However, they do not include the great apes.
“Because Sterkfontein contains the largest concentration Australopithecus fossils from an individual site of Africa, it has been a crucial part of research and debates about our ancestry,” Kathleen Kuman, who was part the Purdue University research team, said to NBC News.
Kuman, an emeritus professor at the University of the Witwatersrand added that the new data “show that these South African hominid fossils were largely contemporan with species in East Africa like Australopithecus.afarensis, and are unlikely to have been their descendants, better revealing the complex nature of how species evolved in the distant past.”
Purdue University released a press release stating that Lucy, Dinkinesh, and Australopithecus Africanus, Lucy’s species, date back to around 3.9 million years ago. The university also stated that they used new technology to date the fossils from South Africa. Scientists had previously believed the fossils were between 2 and 2.5 million years old.
This study has rekindled the debate about the origins and evolution of modern humans.
Kuman stated, “The new dates help us to place these evolutionary developments more precisely in time.”
Study lead Darryl Granger’s team used accelerator mass spectrometry to measure radioactive nuclides in the rocks, as well as geologic mapping to help date the Australopithecus-bearing sediments at Sterkfontein, Purdue University said in the news release.
It said that although the Sterkfontein Cave system preserves a long history hominin occupation in this area, dating fossils can prove difficult because rocks and bones have tumbled to ground level.
It was added that dating fossils in East Africa is much easier as researchers can use layers made of volcanic ash to determine their age.
