Webinar in french presented by Alain Lachapelle. Since the British researcher Alec Jeffreys confirmed in 1984 by DNA tests the identity of a As a Ghanaian child threatened with expulsion, the genetic genealogy has continued to develop. Employed today to elucidate historical controversies, to solve resolved, to identify the biological parents of an adopted child or simply to bring out of "family tree breaks" (non-parental events) in classical genealogy, DNA tests have become a complementary but essential tool for any self-respecting genealogist. What are these tests? What can they find? What are their limits? This is what I will have the pleasure to make you discover throughout this webinar!