Ancient DNA perspectives on North American cervids identify fluctuations in genetic diversity
Year: 2026
Type: preprint
Abstract: North American fauna has experienced major changes over the last two million years. Glacial cycles, animal migrations, peopling waves, and, more recently, European colonisation, caused demographic fluctuations, divergence, and wildlife extinctions. Caribou ( Rangifer tarandus ), moose ( Alces alces ), wapiti ( Cervus canadensis ), white-tailed ( Odocoileus virginianus ) and mule deer ( O. hemionus ) are the five extant cervids in Northern America, with unique dispersal patterns and conservation statuses. Here, we used DNA analysis of ancient, historical and modern individuals of these Cervidae to retrace evolutionary processes through time. We show that present-day eastern Canada caribou share ancestry with a 30-thousand-year-old sample from western Canada consistent with the species’ complex dispersal history as suggested by literature. Our results suggest rapid expansion of moose following their arrival on the continent ∼15 thousand years ago. Data on wapiti shows a recent loss of diversity consistent with its large-scale extirpation after European colonisation. Results on Odocoileus species are in line with their recognised mito-nuclear discordance. Our results exemplify the utility of chronological sampling to gain a better understanding of how external pressures drive genomic changes. Significance statement North America has had a dynamic history over the last two million years, with glacial cycles, peopling waves, mammalian extinction events, and European colonisation impacting the regional fauna, including the five deer species currently inhabiting Canada and the USA. It remains unclear how those events impacted each species’ genetic diversity and evolutionary history. Analysis of DNA from samples spanning the last 30 thousand years show signs of expansion after the Last Glacial Maximum for several species, but more recent data shows higher population structure and lower diversity in some cases. Our results indicate each deer species had a unique evolutionary history on the continent, with what appeared to be larger subpopulation ranges during the Holocene whereas more recent times involved more pressures, likely in the form of habitat fragmentation caused by human impact.
Institutions: Trent University, Royal Ontario Museum, Royal Alberta Museum
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7164536962