Once abundant across North America, bison faced near-extinction due to relentless hunting, leading to significant changes in their genetic makeup. New DNA research has unveiled insights into this transformation, tracing the journey of bison herds over 20,000 years.
The study, detailed in the journal Science, involved sequencing 160 bison genomes with the collaboration of nearly 40 scientists, primarily from Canada. Led by Jonas Oppenheimer, a paleogeneticist at the Paleogenomics Lab of the University of California, Santa Cruz, the research focused on unraveling the genetic history of bison to aid modern conservation efforts.
The findings highlight the genetic diversity loss in present-day bison due to the fragmentation of herds, which poses challenges to their resilience. Oppenheimer emphasized the genetic distinctiveness among contemporary bison herds compared to their ancestors, underscoring the impact of past population bottlenecks.
Evolutionary Insights
By analyzing ancient and modern bison DNA, researchers pieced together the genetic puzzle of the species’ evolution. Samples were obtained from managed herds in Canada and the U.S., as well as from preserved specimens in various collections. This comprehensive approach resulted in the largest genetic map of bison to date.
Chris Jass, a paleontologist at the Royal Alberta Museum, hailed the study as a milestone in understanding bison genetics and ecosystem management. The study’s significance lies in its ability to inform conservation strategies and promote genetic diversity among bison populations.
The research sheds light on the historical and recent declines in bison populations, attributing the genetic survival to the broad distribution and uniformity of herds before the devastating population crashes in the late 19th century. Despite subsequent genetic divergence, remnants of genetic diversity have endured in isolated herds.
Genetic Variability
Contrary to popular belief, the study revealed minimal cattle ancestry in bison genomes, emphasizing the distinctiveness of wood bison and plains bison populations. These subspecies diverged around 3,000 years ago due to environmental shifts, with subsequent human interventions further influencing their genetic makeup.
Greg Wilson, a bison geneticist at Parks Canada, stressed the importance of managing bison herds separately based on their genetic differences. Efforts to preserve the genetic integrity of wood bison are crucial, as indicated by the study’s findings.
The study’s implications extend to conservation practices, suggesting the need for genetic matchmaking to mitigate inbreeding risks and enhance genetic diversity among bison herds. By leveraging ancient genomes, conservationists aim to restore natural gene flow and safeguard bison populations for future generations.
‘Preserving Bison Heritage’
Wilson, along with the Bison Integrated Genomics team, conducted the genome study to advance bison conservation through genetic preservation and the establishment of a bison genome biobank. The study’s outcomes offer a roadmap for reconnecting disjointed bison herds and counteracting the genetic repercussions of past population declines.
Ancient genomes serve as benchmarks for managing bison herds sustainably, ensuring their genetic diversity thrives in the wild. Maintaining genetic variation across bison populations is crucial to their long-term viability and ecological resilience.
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