Another human example is the sequencing of mitochondrial DNA from Neanderthal bones. No evidence of Neanderthal mitochondrial DNA has been found in modern humans. Genetic studies on Neanderthal ancient DNA became possible in the late 1990s. The remains present a mixture of archaic, early modern human and Neanderthal morphological features. The modern human papillomavirus variant 16A may descend from Neanderthal introgression. Interbreeding can only account for a certain degree of Neanderthal population decrease. It continued to exist until around 30,000 BP, when Neanderthal man faced extinction. This is consistent with the apparent 150 ka stagnation in Neanderthal lithic technology. It is also proposed that one cause of Neanderthal extinction was a less efficient running. The exhibit highlights an actual fossil Neanderthal and replicas created by famed paleoartist, John Gurche. Rates of selection against Neanderthal sequences varied for European and Asian populations. Almost everything about Neanderthal behaviour remains controversial. He is the young son of a Neanderthal tribal chief. No claim of a deliberate Neanderthal burial is universally accepted. The film "Iceman" (1984) told the story of the reanimation of a frozen Neanderthal.