Bison, once abundant across North America, faced near extinction due to human activities. Recent DNA research sheds light on their genetic history and the impact of their dwindling populations on their genetic diversity.
The study, detailed in the journal Science, involved sequencing 160 bison genomes from various time periods, providing insights into their past over 20,000 years. Led by paleogeneticist Jonas Oppenheimer and the Paleogenomics Lab at the University of California, Santa Cruz, the research engaged nearly 40 scientists, many of whom were Canadians.
By deciphering the complex genetic makeup of bison, researchers aim to enhance conservation strategies to ensure the species’ future survival. They discovered that modern bison herds, once interconnected, are now fragmented, posing challenges to their resilience.
Oppenheimer noted that historical bison populations were genetically similar, but today’s herds exhibit significant genetic variation, a consequence of past human-driven population bottlenecks leading to their dramatic decline.
Genetic Mapping and Diversity
Through genome sequencing of ancient and modern bison samples, researchers tracked changes in the species’ biological diversity over time. The study included DNA samples from managed herds in Canada and the US, as well as ancient specimens from collections worldwide.
The research analyzed 115 ancient bison genomes and 45 modern ones, combined with existing data, to create a comprehensive genetic map of bison. This study, emphasizing collaboration, highlighted the importance of ancient fossils in modern conservation efforts.
The decline of bison populations in the late 19th century due to hunting and human activities led to a change in genetic diversity. Despite the species’ genetic resilience, today’s herds exhibit distinct genetic signatures, reflecting their fragmented history.
Distinct Bison Subspecies
Contrary to popular belief, the study revealed that bison have minimal cattle ancestry, with wood bison and plains bison being genetically separate. Wood bison, suited to northern forests, and plains bison, native to grasslands, diverged around 3,000 years ago due to environmental changes.
Interbreeding between subspecies in the past has influenced their genetic makeup, emphasizing the need for separate management approaches. Bison geneticist Greg Wilson stressed the importance of preserving distinct subspecies for conservation purposes.
‘Conservation Strategies’
Collaborative efforts like the Bison Integrated Genomics project aim to conserve bison populations through genetic preservation. Researchers advocate for genetic matchmaking among isolated herds to prevent inbreeding and restore genetic diversity.
By utilizing ancient genomes as references, conservationists can reintroduce gene flow among bison herds to improve genetic diversity and promote the species’ long-term survival in diverse landscapes.
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