The voice of our ancestors

An ancestor is a progenitor from which individuals or groups are descended. Some research suggests that the average person has twice as many female ancestors as male ancestors. This might have been due to the past prevalence of polygynous relations and female hypergamy.[3] Assuming that all of an individual's ancestors are otherwise unrelated to each other, that individual has 2n ancestors in the nth generation before them and a total of 2g+1 − 2 ancestors in the g generations before them. In practice, however, it is clear that most ancestors of humans (and any other species) are multiply related (see pedigree collapse). Consider n = 40: the human species is more than 40 generations old, yet the number 240, approximately 1012 or one trillion, dwarfs the number of humans who have ever lived.