"In the cases of three species of matrilineal cetaceans, including pilot whales, sperm whales, and killer whales, mitochondrial DNA nucleotide diversities are about ten times lower than other species of whale.Whitehead found that this low mtDNA nucleotide diversity yet high diversity in matrilineal whale culture may be attributed to cultural transmission, since learned cultural traits have the ability to have the same effect as normal maternally inherited mtDNA.