Researchers have recovered DNA from four people who lived in the present day Cameroon dating as far back as 8,000 years ago.
“Here we report genome-wide DNA data from four children—two of whom were buried approximately 8,000 years ago and two 3,000 years ago—from Shum Laka (Cameroon), one of the earliest known archaeological sites within the probable homeland of the Bantu language group,” the scientists said in the journal Nature.
With the new discovery, the researchers said modern humans diverged into four major populations between 200,000 and 250,000 years ago. One of those populations is new to scientists; few traces of it remain in the DNA of living Africans.
“Our knowledge of ancient human population structure in sub-Saharan Africa, particularly prior to the advent of food production, remains limited,” the scientists said, but the new discovery has given us a bit more knowledge.
The scientists said one of the four individuals “carried the deeply divergent Y chromosome haplogroup A00, which today is found almost exclusively in the same region”.
“However, the genome-wide ancestry profiles of all four individuals are most similar to those of present-day hunter-gatherers from western Central Africa, which implies that populations in western Cameroon today—as well as speakers of Bantu languages from across the continent—are not descended substantially from the population represented by these four people,” the scientists clarified.
“We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one that gave rise to at least four major lineages deep in the history of modern humans”.
The New York Times quoted Jessica Thompson, an archaeologist at Yale University who was not involved in the new study as saying “We are so limited by the information we can get from living people”, adding that “It’s pretty clear that there’s been a huge transformation in the genetic landscape in Africa just recently.”
The New York Times noted that: “Scientists have been studying the genetic diversity of living Africans since the 1970s. As it became possible to sequence more DNA, the additional data revealed that the genetic variation among living Africans was much greater than that among the rest of the world combined.
“This insight made it clear that our species arose in Africa and stayed there for most of its history. Small groups of people expanded out to give rise to non-African populations.
“But scientists have struggled to draw the older branches of the human family tree with much precision. Looking for fresh clues, they tried drilling into ancient bones”.