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Publication

New publication – Genomic signatures of population bottleneck and recovery in Northwest Atlantic pinnipeds

By | Publication

The recent recovery of gray and harbor seals in the Northwest Atlantic, following historical exploitation and subsequent protection, provides a natural “experiment” in which to evaluate the impact of changes in population size and distribution on genetic diversity.  It is a rare opportunity to test evolutionary theories, for example that genetic bottlenecks will reduce diversity (in extreme cases, leading to inbred populations), in a natural population.  With a genomic approach, called RAD sequencing, we evaluated how diversity has changed over time and space in multiple cohorts of gray and harbor seals sampled over the past half-century.  Our findings clearly show that signatures of historical bottleneck remain in the genomes of the species today, but also find high contemporary diversity, suggesting the species are not inbred.  Interestingly, we find higher diversity in gray seals than harbor seals, which may have important implications for species fitness, a point we’d like to continue to investigate moving forward.

Co-authors on this paper include collaborators from the Duke University Marine Lab, NOAA NEFSC, Canada DFO, Tufts University, and St. Mary’s University.  If you’re interested in other research we’ve done on this topic, check out our comparison of contemporary and archaeological seals from this region.

A full, freely available copy of our new open-source paper can be found here, or feel free to contact me directly for more information.

Cammen KM, Bowen WD, Hammill MO, Puryear WB, Runstadler J, Wenzel FW, Wood SA, Frasier TR, Kinnison M (accepted) Genomic signatures of population bottleneck, recovery, and expansion in Northwest Atlantic pinnipeds. Ecology and Evolution.

 

New publication – Comparing DNA of archaeological and contemporary seals

By | Publication

We are pleased to announce the recent publication of our study of genetic diversity among archaeological and contemporary gray and harbor seals from the Northwest Atlantic.  In our paper, we describe finding greater genetic diversity in both seal populations prior to the bounties of the early and mid-1900s.  We further present evidence that is consistent with the potential loss of a historical Maine subpopulation of gray seals.  These findings are significant to the discussion of how to manage gray and harbor seals today as their populations recover along parts of Maine, Massachusetts, and the Canadian Maritimes.

The co-authors on this paper include undergraduate Sarah Vincze, graduate student Sky Heller, and professor Mike Kinnison from the University of Maine, as well as collaborators from NOAA NEFSC, Canada DFO, Tufts University, and St. Mary’s University.  The project was enhanced by the diverse perspectives of geneticists, ecologists, field biologists, and archaeologists.

Our paper can be found here, or feel free to contact me directly for more information.

Cammen KM, Vincze S, Heller AS, McLeod BA, Wood SA, Bowen WD, Hammill MO, Puryear WB, Runstadler J, Wenzel FW, Kinnison M, Frasier TR (2018) Genetic diversity from bottleneck to recovery in two sympatric pinniped species in the Northwest Atlantic. Conservation Genetics. 19: 555-569.

 

New publication: Cost of tolerance

By | Publication, Research

In collaboration with new marine physiology professor, Nishad Jayasundara, and collaborators at Duke University, we’ve published our findings on the cost of evolving tolerance to anthropogenic pollutants in the Atlantic killifish.  These fish represent a “natural experiment” in which to study the evolution of toxin resistance; they have evolved the ability to survive exposure to high levels of PAHs, making it possible to inhabit Superfund sites in the Elizabeth River, Virginia.  In this system, our new paper explores the hypothesis that the evolution of resistance to one stressor makes organisms more susceptible to other stressors.  For more information, check out our paper here.