The site has yielded the oldest human remains ever to be found in Bulgaria. At one of the earliest known
Aurignacian burials (layer 11), two pierced animal teeth were found and ordered into the distinct
Bachokiran artifact assemblage.
Radiocarbon dated to over 43,000 years ago, they currently represent the oldest known ornaments in Europe. With an approximate age of 46,000 years, human fossils consist of a pair of fragmented
mandibles including at least one
molar. Whether these early humans were in fact
Homo sapiens or
Neanderthals was disputed until morphological analysis of a tooth and mitochondrial DNA of bone fragments established that remains were those of
Homo sapiens. In samples F6-620 and AA7-738 identified
mitochondrial haplogroup M, in samples WW7-240 and CC7-335 determined the
mitochondrial haplogroup N, in sample CC7-2289 identified
mitochondrial haplogroup R, in sample of BK-1653 identified
mitochondrial haplogroup U8. Three
Initial Upper Paleolithic individuals (c. 44,000 to 40,000 years ago) from Bacho Kiro cave were each found to have relatively high levels of Neanderthal ancestry, with their genomes suggesting a recent Neanderthal ancestor in all three individuals perhaps six or seven generations back. In the single dispersal
Out of Africa theory, it is believed that populations related to the Initial Upper Palaeolithic population of Bacho Kiro cave contributed ancestry to later Asian populations and early West Europeans such as the c. 35,000 year old individual from the
Goyet Caves, Belgium, known as 'GoyetQ116-1'. Populations related to these earlier individuals did not contribute detectable ancestry to later European populations. individuals from Bacho Kiro were closer to the
Tianyuan man, and to modern-day East Asians, Central Asians and Native Americans, than to Europeans or Africans. However, in the multiple dispersal
Out of Africa theory, East Asians are found to have a more distant split time from East African populations (73,000 to 88,000 years ago) compared to modern Europeans (57,000 to 76,000 years ago) which could mean that the Bacho Kiro remains could be from a migration of
anatomically modern humans from Asia. In 2022, a study determined that the IUP-affiliated Bacho Kiro remains were part of an
Initial Upper Paleolithic wave (at least 45,000 years ago) "ascribed to a population movement with uniform genetic features and material culture" (
Ancient East Eurasians), and sharing deep ancestry with other ancient specimens such as the
Ust'-Ishim man and the
Tianyuan man, as well as ancestors of modern-day
Papuans (Australasians). The Bacho Kiro population was also closely related to the
Peștera cu Oase specimens, which both were associated with the IUP material culture in Europe, and got absorbed by the later Upper Paleolithic migration wave associated with
West Eurasians (represented by the
GoyetQ116-1 and
Kostenki-14 remains). Around 19% ancestry of the GoyetQ116-1 individual is derived from a Bacho Kiro IUP-like source, while up to 39% ancestry of the
Tianyuan man is derived from an IUP-affiliated source distantly related to the Bacho Kiro IUP remains, explaining the unusual affinity between GoyetQ116-1 and Tianyuan. Following that, later individuals from the Bacho Kiro Cave, such as the c. 35,000 year old 'BK1653' were more closely related to modern European populations than to East Asians. ==See also==