The Contribution of Irish Immigrants to the Quebec (Canada) Gene Pool: An Estimation Using Data from Deep-Rooted Genealogies

European settlement in Quebec (Canada) began in the early 17th century, with the arrival of French pioneers. After the British Conquest in 1760, immigrants from the British Isles began to settle in some parts of Quebec. Many of these immigrants were Irish Catholics. Historians and genealogists have identified several names of Irish origin in the French Canadian population, and many scholars have wondered about the importance of the integration of Irish migrants and their descendants within this population. The purposes of this study are to identify and characterize the founders of Irish origin to estimate the importance of their genetic contribution to the contemporary Quebec population, and to measure the variability of this contribution according to the founders’ period of arrival and county of origin in Ireland. Data was obtained from a set of 2,223 ascending genealogies going back as far as the early 17th century. The average genealogical depth is a little more than 9 generations, with many branches reaching 16 or 17 generations. Although Irish founders explain less than 1% of the total Quebec gene pool, results show that nearly 21% of the genealogies contain at least one Irish founder. These founders contributed to the peopling of all regions of Quebec, but there are some important variations from one region to another. A majority of the Irish founders immigrated during the 19th century, and most of them came from the counties of Southern Ireland.