Human evolution has an essential chapter: the transition between Neanderthals and Homo sapiens, which ended with the survival of the latter after this transition. The emergence and spread of modern humans in Europe is a complicated timeline to rebuild due to the scarcity of sufficiently old remains in the fossil record. An international team of researchers has discovered that the first of our species in Europe occupied a cave formerly inhabited by Neanderthals nearly 46,000 years ago, which means this cultural transition occurred earlier than what was previously thought.
A clearer timeline
Until now, most of the first human fossils on the continent were between 41,500 and 45,000 years old. However, those ages are based on dates of sediments and artefacts associated with fossils, not fossils per se. The new findings, a tooth and six bone fragments, as well as other artefacts found deep in Bulgaria’s Bacho Kiro cave (at the foot of the Balkans) are the oldest remains of Homo sapiens with direct date in Europe, scientists say. They date from 44,000 to 46,000 years old and add scientific evidence from a scenario in which African H. sapiens arrived in the Middle East about 50,000 years ago and then dispersed rapidly in Europe and Central Asia, according to experts in the magazine Nature.
Bacho Kiro is a rich deposit of Palaeolithic fossils that extends more than 3,500 metres through Palaeolithic galleries and whose re-excavations of the site began in 2015 (the first excavations date back to the 1970s but the human remains discovered were eventually lost). The excavation revealed a layer of sediment containing what appear to be the oldest human remains of our migrant ancestors ever identified in Europe.
"Most of the bones of the Pleistocene are so fragmented that, to the naked eye, it is impossible to know what species of animal they represent," stated human evolution researcher Frido Welker of the Max Planck Institute for Evolutionary Anthropology in Germany and co-author of the paper.
Using various methods that incorporate radiocarbon dating and mitochondrial DNA sequencing to estimate the age of fossils, the researchers concluded that these ancient humans probably occupied the cave from approximately 43,650 to 45,820 years ago, although some of the remains could be traced up to 46,940 years ago.
"Therefore, as far as we know, these bones represent the oldest European hominids from the upper Palaeolithic recovered to date," the authors explain in one of the two new articles describing the findings.
Amongst the artefacts discovered, various ornaments, tools, weapons and a pendant made with bear teeth resemble those found in earlier places associated with the Neanderthals, which suggests that there was interaction between the two groups prior to the eventual disappearance of the latter.
"The Early Upper Paleolithic in Bacho Kiro Cave is the oldest Upper Paleolithic known in Europe. It represents a new way of making stone tools and new behavioral sets, including making personal ornaments that mark a differentiation from what we know of the Neanderthals up to this point,” Tsenka Tsanova, from the Department of Human Evolution at the Max Planck Institute of Evolutionary Anthropology stated.
Experts point out that "the ongoing work in this area is crucial" to understanding the timing of major events in hominid adaptations and demographic processes during this period in human history.
Reference: Initial Upper Palaeolithic Homo sapiens from Bacho Kiro Cave, Bulgaria, Nature (2020). DOI: 10.1038/s41586-020-2259-z , www.nature.com/articles/s41586-020-2259-z
A 14C chronology for the Middle to Upper Palaeolithic transition at Bacho Kiro Cave, Bulgaria, Nature Ecology & Evolution, DOI: 10.1038/s41559-020-1136-3 , www.nature.com/articles/s41559-020-1136-3