mtDNA control region
The mutation rate of the mitochondrial control region has been widely used to calibrate human population history.
References
Sigurgardottir S, Helgason A, Gulcher JR, Stefansson K, Donnelly P. The mutation rate in the human mtDNA control region. Am J Hum Genet. 2000 May;66(5):1599-609. PMID: 10756141