Genetic history celebrates divers …



(Photo: Duncan P Walker / / Wikipedia)

From the history of migration and movement of early humans, we understand the adjustment to settlement and how the rise of civilizations came about. There are also unexpected twists and turns in procreation that have given us a continuous genetic mix.

First published in the Daily Maverick 168 weekly newspaper.

“We are all bastards – the idea of ​​a pure population does not exist,” says Professor Himla Soodyall.

In the fragmented and divided society of 2021, the geneticist insists on this point. This is because it is not the only story from us. At the level of our DNA, another story also stands – one where the rich diversity of who we are today converges as an ancient truth of common heritage.

“Anyone alive today can see themselves as a leaf on a tree placed on a small branch which ends up connecting to larger branches which are ultimately connected to a common trunk. And the path of the branch is based on the movement and collective history of your ancestors, ”says Soodyall.

Understanding the tangled paths of these metaphorical branches gives us clues to understanding our evolutionary journey. It is from the moment we dragged our fingers, hunched close to the ground, to evolve to use tools for a determined result.

The first humans all migrated out of sub-Saharan Africa between 100,000 and 200,000 years ago, then settled with their pets and crops. Today we envision the future of gene editing for disease-free offspring, perhaps also green-eyed babies on demand, and mammoths returning to rehab somewhere in the tundra.

To the story told through our genes are added layers of evolution from other disciplines, such as history, geology, archeology, biology, anthropology and linguistics. Combined, they give us a clearer picture of the reasons and likely effects of the unfolding of human history.

From the history of migration and movement of early humans, we understand the adjustment to settlement and how the rise of civilizations came about. There are also unexpected twists and turns in procreation that have given us a continuous genetic mix. Crosses between different populations and even species have occurred. Humans from different groups have bred with each other as well as with Neanderthals and other now extinct hominid species.

We are seeing clues about the changing climatic conditions and how our early ancestors reacted and adapted, or not. He presents the evidence to see how different today’s climate crisis is in its rapid acceleration over just a few decades.

Genetic testing can drag the thread of history to the present day. In recent years, a large-scale genetic collection and testing project among the African diaspora in the Americas has gone devastatingly to tell the story of transatlantic slavery.

He holds the overwhelming evidence of the extent of the rape of female slaves by their white masters that took place.

From the broad lines of genetic evolution are born the great nuggets that fill our histories. This is how cultural norms and rituals were formed due to their power to order the unknown.

A digital representation of the human genome at the American Museum of Natural History in New York. Each color represents one of the four chemical components of DNA. (Photo: Mario Tama / Getty Images)

The rise of religions, philosophies and belief systems came to establish limits and codes that demarcated initiates from outsiders. Identities took shape and the personal became the always political. We came to see what we were in danger of losing; also see who we could benefit from. It’s human nature, but it’s also our choice to choose better.

For Soodyall, who is the executive director of the South African Academy of Sciences (ASSAF), distinguishing between identity and ancestry is an essential starting point for a debate on genetic history and heritage.

Knowing the difference means that a more in-depth calculation should also take place.

“We are the product of many iterations of how our male and female lineages of our ancestry have blended together over the eons. So when do you want to take your ancestry? Because everyone should ask themselves, “How far do I want to look for my answers?” “

“I still see heritage as an aggregation of various aspects of bringing disciplines together because, as a society, we all have different values ​​and cultures. “

Identity, for example, claims genetics for first nation status as a hallmark of today; it can also be used for convenient otherness that feeds xenophobia and racism; and is hijacked for supremacist fictions.

The genetic background, however, is unequivocal; it provides you with “an unbiased record of your past” – and it is up to everyone to find a point of origin on Soodyall’s metaphorical tree trunk, where we are not so different after all.

“We need to be able to debate in a respectful way, not in a way that demands power, shows dominance or brings prestige to one at the expense of another.

“We’re all members of a few, many, many things. And the thing that sets us apart from the next person is how we engage intellectually, mentally, and spiritually.

“Our biases are in our expression of things that we have learned over time to discriminate on the basis of physical appearance.”

Our collective heritage history through the prism of genetic science is a way to celebrate the diversity and complexity of human history. The wider the field and the deeper the research analysis, the more we can sit with the points of tension.

Discomfort with truths can inform conscious repair and restitution, perhaps also reflection – not the knee-jerk reaction of seething retreat, insularity, retaliation and revenge.

Heritage, at the genetic level, connects us all. How we came to be and survive on our exquisite piece of rock is the origin story to which we collectively claim.

Mapping humanity

For a decade and a half, South Africans participated in National Geographic’s Genographic Project. The global project began in 2005 to use advanced DNA analyzes within indigenous communities and the general public to find answers about how people came to populate the Earth.

From its two 15-year phases, the project has successfully obtained genetic samples from 745,000 people from over 140 countries. It has created “unprecedented information on their ancestral makeup from the more than 300,000 DNA markers that have been analyzed,” National Geographic said.

The scale of the project and the size of the sample were decisive in the mapping of migratory patterns dating back 150,000 years.

It was a boon to the genetic sciences, also helping to arouse public curiosity and build bridges for better scientific communication between the ivory towers of science and the common man.

Professor Himla Soodyall, who led the South African sample collection at Wits University’s Origins Center, says: “The people who participated were coming in for the tests and had so many questions to ask; it was a question of accessing a scientist who could give them answers.

Soodyall understands that the real value of science comes when the public can share the results and can see themselves mapped into the data.

She says ASSAF will continue to showcase the work of leading scientists and researchers and make discoveries in genetic science more accessible and accessible to the general public.

Although private companies continue to provide genetic testing kits and analyzes for growing consumer demand for personal genetic testing and genealogy tracing, the National Geographic Genographic Project was discontinued in January 2020.

The Wits Origins Center, which collaborated with the National Health Laboratory Services on the project, stopped collecting, testing, and analyzing ancestral DNA a few years earlier. DM168

This story first appeared in our weekly Daily Maverick 168 which is available for R25 from Pick n Pay, Exclusive Books and airport bookstores. For your nearest dealer, please click here.


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