 Using various statistical methods, they estimated the divergence time human-chimp to be 4.7 MYA and the divergence time between gorillas and humans (and chimps) to be 7.2 MYA.Additionally they estimated the effective population size of the common ancestor of humans and chimpanzees to be ~100,000.This was somewhat surprising since the present day effective population size of humans is estimated to be only ~10,000.