Evolution in action: tuberculosis influences immune genetics in wild meerkats

A groundbreaking long-term study into a population of meerkats in Africa has revealed how evolutionary changes can be driven by a lethal pathogen.

An international research team led by scientists from Ulm University, Germany, with colleagues at the University of Salford, have been part of a unique long-term study of meerkats in the South African Kalahari Desert.

Over two decades, the researchers tracked how the spread of a meerkat-specific form of tuberculosis—caused by the bacterium Mycobacterium suricattae—not only affected the animals’ survival and reproduction but also altered their immune genetic diversity over time. The findings, published in the journal Nature Ecology & Evolution attribute these changes to the selective pressure of the pathogen, which is becoming more common with climate change.

The research integrated genetic data from over 1,500 meerkats from one of the world’s most thoroughly studied wild populations. Alongside genetic analyses, extensive health and survival records were collected. This wealth of data, combined with decades of research, enabled the team to show how a previously disadvantageous immune gene variant has gradually become more common —likely driven by shifts in the co-evolutionary relationship between host and pathogen. Until now, such dynamic adaptive processes had only been inferred from laboratory or cross-sectional studies.

“Our data demonstrate how pathogens can trigger evolutionary changes in wild populations in real time,” says lead author Dr. Nadine Müller-Klein from Ulm’s Department of Evolutionary Ecology and Conservation Genomics.

Particularly concerning is the finding that the spread and progression of meerkat Tuberculosis has been exacerbated by higher temperatures and reduced rainfall in the area due to climate change. These results highlight the growing importance of wildlife diseases within the broader context of human-driven environmental change.

“Climate change not only alters habitats, but also the way infectious diseases affect the health of wildlife,” explains Ulm co-author Dr. Dominik Melville. “Food shortages and heat stress deplete energy reserves – this becomes particularly critical when an animal is already weakened or infected.”

Dr Alice Risely, of the University of Salford, and co-author on the paper, said: “Very few studies that have looked at a wild population like this and how they evolve to resist new pathogens.

“Genetics might give you new forms of resistance but pathogens will quickly adapt. What are the dynamics between those processes? Long-term ecological datasets like this, which allow scientists to test such questions, are extremely rare.”

“Twenty years ago, we already recognized that maintaining genetic diversity would be crucial for conservation,” says Prof. Simone Sommer, senior author on the study.

“Now we see that especially immune genetic diversity can enhance disease resilience in the face of climate change,” she adds on an optimistic note. However, the wildlife ecologist warns that conservation efforts must not be weakened now.