Title: The population genomics legacy of the second plague pandemic in Trondheim, Norway

Abstract:      

The second plague pandemic, beginning ca. 1347 AD, devastated urban populations in large swathes of Europe, reducing population sizes in most urban centers by 10 - 40% in the span of a few years. In this talk, I will focus on the city of Trondheim in Norway, which according to some historians lost up to 70% of its population during the pandemic. Using a combination of pre-pandemic, post-pandemic and modern samples from the city of Trondheim, we investigate the signatures left by the second plague pandemic on the genomes of Trondheimers. Our study shows that the urban population loss was most likely replaced by local rural populations in the city. Further, we find large parts of the genome showing evidence of frequency changes between the pre- and post- pandemic populations. But our findings are heavily tempered by evidence of large scale differential reference bias across the genomes. We are following up with a larger study in Trondheim, and a follow-up study in Lund to test if similar genomic regions are found to be differentiated between pre- and post- pandemic populations in these follow up studies.