Assuming you have 44,000 genes (a copy from each parent) and random recombination each generation, then some of your ancestors will have stoped contributing gen

Assuming you have 44,000 genes (a copy from each parent) and random recombination each generation, then some of your ancestors will have stoped contributing genes by 16 generations (400 years). These assumptions arent perfect, but givebyou a sense of what happens. (People have far fewer than 2^N ancestors due to distant cousin inbreeding) (Genetic recombination is not random, but chunky.)