A long time ago, bison roamed North America in vast herds of rust and auburn fur before being nearly wiped out. New research on their DNA sheds light on how their decline and gradual return have reshaped the species. The study, detailed in the journal Science, analyzed 160 bison genomes spanning 20,000 years, involving nearly 40 scientists, including many Canadians.
Led by paleogeneticist Jonas Oppenheimer at the Paleogenomics Lab, University of California, Santa Cruz, the research aims to aid modern conservation efforts by understanding the bison’s genetic history. Once well-connected, bison now exist in fragmented populations, affecting their resilience.
The genetic sequencing showed that modern bison herds face challenges due to their genetic differences, a result of a historic bottleneck caused by human activities. By comparing ancient bison DNA with modern herds, researchers observed changes in genetic diversity over time.
The study revealed that despite a significant decline in population due to hunting and government actions in the late 19th century, genetic diversity initially remained intact. However, the surviving diversity is now scattered across isolated herds, each with its unique genetic signature.
Contrary to common belief, the research found that many bison have minimal cattle ancestry. Wood bison and plains bison were also found to be distinct species, with wood bison adapted to northern forests and plains bison to grasslands.
The study suggests that maintaining the separate management of these species is crucial due to their genetic diversity. Efforts to preserve wood bison as a distinct subspecies are recommended, as they represent a significant genetic split from plains bison.
Researchers emphasized the importance of genetic matchmaking among bison herds to prevent further loss of genetic diversity. By leveraging ancient genomes, conservationists can facilitate gene flow among isolated herds, ensuring the preservation of genetic diversity and enabling bison to thrive in their natural habitats.
