Kenya’s Turkana people genetically adapted to live in harsh environment, study suggests | Global development

A collaboration between African and American researchers and a community living in one of the most hostile landscapes in northern Kenya has revealed key genetic adaptations that explain how pastoral people were able to prosper in the region.

According to a study published in Science, underlying the population’s capacities to live in Turkana, a place defined by extreme heat, water shortage and limited vegetation, was hundreds of years of natural selection.

It shows how the activity of key human genes has changed during millennia and results place “Turkana and sub-Saharan Africa at the forefront of genomic research, an area where indigenous populations have historically been under-represented”, according to Charles Miano, one of the co-authors of the study and a post-university student in Kenya Medical Institute (Kemri).

Research sequered 367 whole genomes and analyzed more than 7 million genetic variants, identifying several regions of the genome under natural selection. It was produced through the Turkana Health and Genomics Project (THGP), an initiative bringing together researchers from Kenya and the United States, notably Kemri, Turkana Basin Institute (TBI), Vanderbilt university in Tennessee and the University of California in Berkeley.

The genomic analysis found eight DNA regions which had undergone a natural selection but a gene, STC1,, Expressed in the kidneys, he showed exceptionally solid evidence of the adaptation of humans to extreme environments. The evidence included the body’s response to dehydration and the transformation of foods rich in purines such as meat and blood, staples of the Turkana diet.

Turkana extends over a large strip in northern Kenya, one of the most arid regions in the world, where the shadow is rare and even rarer. Precipitation arrives in brief unpredictable gusts and securing enough water for themselves and their herds of cattle, goats and camels are a daily chore. Water recovery can involve trips of several hours each day on hot ground without vegetation.

About 70% to 80% of the community’s diet comes from animal sources, mainly milk, blood and meat, reflecting ingenuity and adaptation to rarity, which is common among pastoral societies around the world living in environments where cultures cannot grow and where markets are too far to be accessible on foot.

However, after years to document the lifestyle of the people of Turkana and to study blood and urine samples to assess their health, the researchers found that, although the community consumes too much purine, which should lead to gout, the condition rarely appears among the Turkana.

“About 90% of people evaluated were dehydrated but generally healthy,” said Professor Julien Ayrroles, from the University of California in Berkeley, one of the project-printing investigators. “The Turkana have maintained their traditional lifestyle for thousands of years, providing us with an extraordinary window on human adaptation.”

The genetic adaptations would have emerged approximately 5,000 years ago, coinciding with the aridification of North Africa, the study suggesting that as a region which has become dry, natural selection favored variants that have improved survival in arid conditions.

“This research shows how our ancestors have adapted to dramatic climate change through genetic evolution,” said Dr. Epem Esekon, head of the County Health and Sanitation sector.

However, while more and more members of the Turkana community move to cities, the same adaptations that used to protect them can now increase the risk of chronic lifestyle disease, a phenomenon called “evolutionary gap”. This occurs when adaptations shaped by an environment become responsibilities in another, stressing that the rapid lifestyle changes interact with deep evolving history.

When the researchers compared biomarkers and the expression of genes – the process by which the information coded in a gene is transformed by function – In the genomes of the Turkana living in town, their parents still living in the villages, they have found an imbalance in the expression of genes which can predispose them to chronic diseases such as hypertension or obesity, which are more common in urban areas where regimes, water availability and models of activity are radically different.

“Understanding these adaptations will guide health programs for Turkana, especially since some go from traditional pastoralism to urban life,” said Miano.

While the world faces a rapid environmental change, the history of the Turkana people offers inspiration and practical ideas. For generations, have said researchers, this community has developed and maintained sophisticated strategies to survive in a difficult and variable environment, knowledge that becomes more and more precious as the climate crisis creates new survival challenges.

For almost a decade, the project focused on co -production of knowledge, combining genomic science with ecological and anthropological expertise. The agenda has emerged from dialogue with the former Turkana, scientists, chiefs and community members, health, diet and change, often in the evening around a campfire.

“Working with the Turkana has been a transformer for this study,” said Dr. Sospeter Ngoci Njeru, co-researcher and deputy director of Kemri’s Center for Community Research. “Their information on their environment, their lifestyle and their health has been essential to connect our genetic results to the biology of the real world and to survival strategies.”

Dr. Dino Martins, director of TBI, says that the deep ecological connection and adaptation to one of the warmest and arid environment of the earth provide lessons on how the climate continues to shape human biology and health. “Discovery adds another important knowledge to our broader understanding of human evolution,” he said.

Researchers say that other pastoral communities in similar environments in East Africa, notably, Samburu, Borana, Merille, Karamojong and Toposa, are likely to share this adaptation.

The research team will create a podcast in the Turkana language to share the results of the study and also plans to offer community practical health considerations which arise from rapidly evolving life changes.