Evolution of Inbreeding Coefficients and Effective Size in the Population of Saguenay Lac-St.-Jean (Québec)

We computed mean inbreeding coefficients (FIT, FIS, and FST) based on approximately 2,700 ascending pedigrees of contemporary people from Saguenay Lac-St-Jean (Québec, Canada). This allowed us to appreciate the accumulated inbreeding and to follow the evolution of these coefficients since the founding of Québec. One of the results was the expected increase in FST. Relying on this parameter, we computed the effective size (Ne) of the contemporary population, obtaining a value around 1,000, in agreement with previous estimations. We noticed a decrease of Ne through history despite the population‘s growing size.