Ruminations

Migrating Out of Africa

"We propose that the southwest migrants maintained a successful coastal forager existence, while the northeast migrants gave rise to ancestral pastoral and farming populations."
"Our results suggest that the greater Zambezi river basin, particularly the Kalahari region, had a significant role in shaping the emergence and prehistory of anatomically modern humans."
Nature paper

"Using that we could pinpoint what we believe is our human homeland, what we hadn't known until this study is where exactly this homeland was."
"...Our genetic data suggests the southerly migrants went on to inhabit the entire southern coast of Africa, with multiple sub-populations and huge population growth. Archaeological findings from the Blombos caves in South Africa have shown this region to be rich in evidence for cognitive human behaviour as early as 100,000 years ago. Again, we were amazed at how well we could match timeline data, crossing different yet complimentary disciplines that have historically not worked together. This also allowed us to further speculate about the success of the southerly migrants being attributed to adapting their skills to the abundance of life in the oceans."
"It is now clear our ancestors must have dispersed from a region south of the Zambezi River. This is consistent with geographical, archaeological and climate data, including the fact that this area would have been a fertile wetland at the time the first modern humans emerged."
Dr.Vanessa Hayes, South African research geneticist, Australia

Vanessa Hayes has long studied the Juǀ’hoansi of the Kalahari Desert of Namibia who speak a Khoisan click language. © Chris Bennett/Evolving Picture

A new genomic research paper claims that all humans today were descended from a hunter-gatherer population sustained for tens of thousands of years in a limited-area wetland in modern Botswana, southern Africa. When natural variations in the orbit of the Earth caused a "wobble", climate was affected, the wetland dried up to become part of the Kalahari Desert and the people abandoned this "homeland", according to the theory.

New green corridors were opened, prompting the first human migration to the northeast, then southwest, and eventually covering the globe. When Vanessa Hayes, a research geneticist, flew over the Makgadikgadi Pans National Part in Botswana she could see tectonic fault lines impressed into the dry earth, along with salt pans indicating ancient lakes, dry now for ten thousand years. But before that time, an estimated 200,000 years ago, modern humans arrived in the region as the lake was breaking into smaller lakes and wetlands to crate a lush "oasis" within drier areas.

Makgadikgadi Pans National Park. Getty Images/iStock Photo

Dr. Hayes describes the population as a founding one whose descendants are now everywhere on Earth, a conclusion Australian and South African researchers reached through genomic data from the maternal family tree of humanity overlaid to link with what is known about human geography, linguistics, culture, history, and paleoarcheology. Their paper, published in the journal Nature, claims two major branches on the tree that reaches back to Mitochondrial Eve, the most recent common ancestor of all humans alive today, linking to the study of genetic information, that maternal human phylogenetics was passed from mother to child.

All non-African populations stem from L3, a major branch of the tree when anatomically modern humans departed Africa. The "rare deep-rooting" lineage, L0, clustering in Southern Africa, its origin, was where the research team gathered the mitogenome sequences of 198 southern Africans exhibiting L0, predating the human migration from Africa, offering a unique window into the ancient past, where the research pushes estimated emergence of L0 to 200,000 years, in line with a broader trend in human-origins science, whereas that event was thought to have occurred more recently, 100,000 years ago or even less.

The population, according to the research findings, was sustained around Lake Makgadikgadi for 70,000 years, a verdant homeland eventually disrupted by changing climate caused by the planet Earth's orbital wobble.