If one considers as a function of time t the number of a given individual's ancestors who were alive at time t, it is likely that for most individuals this function has a maximum at around 1200 AD.
時刻tの関数として、時刻tに生きていた個体の祖先の数を考えると、ほとんどの個体にとって、この式は約1200年頃に最大値をとる可能性が高い。