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Bengaluru: A new study suggests that northern Botswana, specifically the region south of the Zambezi river, is most likely the ancestral homeland of all humans.
In the study published in Nature, a group of Australian, Namibian, South African and South Korean researchers combined multiple fields of anthropology, such as ethno-linguistics (relationship between language and ethnic groups), genetics, climatic reconstructions and more, to conclude that our first Homo sapiens ancestors emerged from Makgadikgadi-Okavango, the palaeo-wetland of southern Africa.
Anatomically modern humans (AMH) first walked on Earth roughly 200,000 years ago in Africa. AMH is the phrase used to distinguish Homo sapiens from other extinct hominins such as Neanderthals and Denisovans.
The exact location of the first evolved AMH was unclear before the study — fossil records seemed to indicate it was in eastern Africa, while genetic analysis suggested southern Africa.
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This study is strongly based on genetics, specifically on mitochondrial DNA called mitogenomes. The researchers sequenced mitogenomes of 198 southern Africans and a total of 1217 mitogenomes were analysed. The team also ethno-linguistically classified these individuals as either KhoeSan — those who practice foraging and have a click in their languages who were underrepresented in the genetic database — or non-KhoeSan.
The researchers used phylogenetic analysis (studying the genes to determine genetic evolution) along with language families to reconstruct geographical population dispersals and their common ancestry. This determined that the first genetic lineage settled in the southwest region of the Zambezi river and diverged from here just 60,000 to 70,000 years ago. Archaeological evidence suggests that modern cognitive skills had already started to develop among these humans.
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The paper also states that the Kalahari region in the greater Zambezi river basin had a critical role in shaping the emergence and pre-history of AMHs. The region, which is today made up of salt pans and is considered a semi-arid desert, was once the seat of a gigantic lake tw