Modern humans appeared in East Africa at least 38,000 years earlier than scientists thought. The conclusion was drawn from the traces of a huge volcanic eruption used at the earliest indisputable dates. Homo sapiens fossil.
An archaeological site called Omo I was discovered in the 1960s at the site of Omoki Bish near the Omo River in Ethiopia. Earlier estimates put the human fossils at around 195,000 years old. Today, a new study was published in the journal on January 12. Nature, Another story – the ruins are older than the huge volcanic eruption that rocked the area around 233,000 years ago.
New estimates place the fossils even more firmly in the oldest Homo sapiens It remains to be discovered in Africa and is only the second the 300,000 year old specimen found at the Jebel Irhoud archaeological site in Morocco in 2017. However, the Jebel Irhoud skull is sufficiently different in its physical properties from the human skull modern, and some scientists disagree with the classification. that is why Homo sapiens.. This means that the new findings represent the oldest and undisputed dating of modern humans in Africa.
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“Unlike other intermediaries Pleistocene The fossils would belong to the first stages of Homo sapiens The pedigree, OmoI, has distinct modern human characteristics such as a large spherical cranial vault and a chin,” said Aurélien Mounier, research co-author and paleoanthropologist at the Musée de l’Homme in Paris. .. Said in a press releaseThe spherical skull vault is called the space inside the skull where the brain is located. “The new date quotes effectively make this the oldest undisputed. Homo sapiens In Africa. “
The ruins were found in the Great Rift Valley in East Africa. The East African Rift Valley is an active continental rift zone inhabited by Africans. Structural plate It is splitting into two smaller plates, the Somali plate and the Nubian plate. Despite the discovery of fossils more than 60 years ago, scientists are struggling to maintain Omo I at a decisive age. The fossils had no dating of nearby stone relics or fauna, and the ashes in which they were buried were too fine for radiometric dating. It is a method of quantifying the amount of a particular radioisotope. element The number of neutrons in the nucleus is different), known decay rate.
To avoid these problems, the researchers took samples of pumice from the Shala volcano, more than 248 miles (400 km) away, and ground them to a size of less than 1 millimetre. By performing a chemical analysis of the pumice stone found in the volcano and comparing it to the ash layer of the sediment above where the fossil was found, the researchers were able to confirm that the two shared the same composition. chemical. Same rash. The pumice sample and the ash layer dated to around 233,000 years ago. That is, the Omo I fossils under the ashes are at least the same age or older.
“We first discovered that there was a geochemical consensus, but we didn’t have the age of the Shara eruption,” said Céline Vidal, lead author of the University of Cambridge volcanologist. , in a press release. “I immediately sent a sample from the Shara volcano to a colleague in Glasgow so that I could date the rocks. I received the results and discovered that the oldest Homo sapiens in the area was older than expected. When I was really excited..”
Clive Oppenheimer, a volcanologist at the University of Cambridge, said in a statement that it would not be a coincidence that some of humanity’s earliest ancestors lived in the rift zone. Crustal movement activity not only created lakes to collect stormwater and provide fresh water, but also attracted animals to hunt. The 4,350 mile (7,000 km) Great Rift Valley, which is only part of the East African Rift Valley, has served as a huge moving corridor for humans and animals traveling north since Lebanon to the north. Mozambique to the south.
Despite finding the minimum age of the Omo I specimen, researchers need to find the maximum age of these two fossils and the broader appearance of Homo sapiens in East Africa. They do this by linking more buried ash to more volcano eruptions in the area and giving a stronger geological timeline for the sedimentary layers deposited by fossils in the area. I am planning.
“Our forensic approach provides Homo sapiens in East Africa with a new minimum age, but the challenge of providing the upper limit of their emergence, the earliest age, which is widely believed to have occurred in the region, residence. It remains,” co-author Christine Lane, a geochronologist at the University of Cambridge, said in a statement. “New discoveries and research may enable us to travel back in time to our species.”
Originally posted on Live Science.
Modern humans lived in East Africa 38,000 years earlier than believed Source link Modern humans lived in East Africa 38,000 years earlier than believed